Jahresübersicht für das Jahr 2023

Übersicht 2023 - Übersicht 2024 - Übersicht 2025

05 Jan 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Dr. Nir Bar-Gill, Hebrew University, Jerusalem, Israel
The study of open quantum systems, quantum thermodynamics and quantum many-body spin physics in realistic solid-state platforms, has been a long-standing goal in quantum and condensed-matter physics. In this talk I will address these topics through the platform of nitrogen-vacancy (NV) spins in diamond, in the context of purification (or cooling) of a spin bath as a quantum resource and for enhanced metrology and sensing. I will first describe our work on characterizing noise using robust techniques for quantum control ([1], in collaboration with Ra’am Uzdin). Suppression of such noise can be related to control and cooling of the spin-bath surrounding the NV, using a single optically pumped NV quantum central spin as a refrigerator [2]. I will then present a general theoretical framework we developed for Hamiltonian engineering in an interacting spin system [3]. This framework is applied to the coupling of the spin ensemble to a spin bath, including both coherent and dissipative dynamics [4]. Using these tools I will present a scheme for efficient purification of the spin bath, surpassing the current state-of-the-art and providing a path toward applications in quantum technologies, such as enhanced MRI sensing. Finally, if time permits, I will describe our work in using NV-based magnetic microscopy to implement quantum sensing in various modalities. I will present measurements of 2D vdW magnetic materials, and specifically the phase transition of FGT through local imaging of magnetic domains in flakes of varying thicknesses [5], as well as a technique for sensing radical concentrations through the change in the charge state of shallow NVs ([6], in collaboration with Uri Banin). 1. T. Zabelotsky et. al., in preparation. 2. P. Penshin et. al., in preparation. 3. K. I. O. Ben’Attar, D. Farfurnik and N. Bar-Gill, Phys. Rev. Research 2, 013061 (2020). 4. K. I. O. Ben’Attar et. al., in preparation. 5. G. Haim et. al., in preparation. 6. Y. Ninio et. al., ACS Photonics 8, 7, 1917-1921 (2021).

09 Jan 2023

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., Munich

Nicolo Piazzalunga, Uppsala U.
I'll introduce the higher-rank Donaldson-Thomas theory for toric Calabi-Yau three-folds, within the setting of equivariant K-theory. I'll present a factorization conjecture motivated by Physics. As a byproduct, I'll discuss some novel properties of equivariant volumes, as well as their generalizations to genus-zero Gromov-Witten theory of non-compact toric varieties.
at Zoom

10 Jan 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Nico Döttling, Helmholzt Center for Information Security (CISPA) in Saarbrücken
In the early 1990s cryptography went into a foundational crisis when efficient quantum algorithms were discovered which could break almost all public key encryption schemes known at the time. Since then, an enormous research effort has been invested into basing public key cryptography, and secure computation in general, on problems which are conjectured to be hard even for quantum computers. This research program has been resoundingly successful, leading to unexpected developments, such as the discovery of fully homomorphic encryption schemes. Furthermore, cryptography research has now moved beyond just "post-quantum security”, i.e. security against quantum adversaries, and investigates cryptographic protocols for a (still hypothetical) quantum world, where not just adversaries, but also honest users have access to scalable quantum computers and quantum communication channels. This enables applications such as quantum money, which are impossible using purely classical information. In this talk I will give an overview of the field and some of the (in my opinion) most challenging open problems.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Tim Höhne, TU Dortmund
We address the notorious metastability of the standard model (SM) Higgs potential and promote it to a model building task: What are the new ingredients required to stabilize the SM up to the Planck scale without encountering subplanckian Landau poles? Using the SM extended by vector-like fermions, we chart out the corresponding landscape of Higgs vacuum stability. We find that the gauge portal mechanism, triggered by new SM charge carriers, opens up sizeable room for stability in a minimally invasive manner. We also find models with Yukawa portals into Higgs stability opening up at stronger coupling. Several models allow for vector-like fermions in the TeV-range, which can be searched for at the LHC. For nontrivial flavor structure of Yukawa couplings severe FCNC constraints arise which complement those from stability, and push lower fermion masses up to a few hundred TeV.

11 Jan 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Valentina Santoro, ESS, Lund, Sweden
The European Spallation Source, ESS, currently under construction in Lund, will be the world’s most powerful facility for research using neutrons. Supported by 3MEuro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) is now underway to develop a second neutron source below the spallation target. Compared to the first source, located above the spallation target and designed for high cold and thermal brightness, the new source will provide a higher intensity (the total number of neutrons from the moderator), and a shift to longer wavelengths in the spectral regions of Cold (4-10 ˚A), Very Cold (10-100 ˚A), and Ultra Cold (> 500 ˚A) neutrons. The core of the second source will consist of a large liquid deuterium moderator to deliver a high flux of cold neutrons and to serve secondary VCN and UCN sources, for which different options are under study. The features of this new source will boost several areas of condensed matter research and will also provide unique opportunities in fundamental physics with the neutron antineutron oscillations experiment NNBAR. This experiment will search for the baryon number violating process of n → ¯n oscillation with a sensitivity of three orders of magnitude over the previously attained limit obtained at the Institut Laue-Langevin ILL. As a part of the HighNESS project work is ongoing to deliver the Conceptual Design Report of the experiment. Concerning the design of the Ultra Cold Neutron and Very cold neutron source for the ESS, a digital workshop has been held from February 2nd to February 4th, 2022 where experts from various laboratories and Universities have gathered to propose and discuss ideas and challenges for the development of these sources. During the course of the workshop, several possibilities have been identified on where to locate the VCN and UCN sources. The UCN source could be placed in close vicinity or at some distance from the primary cold source. Regarding the VCN source, we have identified two possibilities. In the first option, the VCNs are extracted from the main CN source using advanced reflectors. While in the other case we make use of a dedicated VCN converter, for which a material capable of delivering a high flux of VCNs is needed. From the point of view of neutronic performance, two promising materials, which are under study in the HighNESS project, are solid deuterium at about 5 K and deuterated clathrate hydrates at around 2 K. In summary in the the talk, the referent will discuss the HighNESS project, the status of the NNBAR experiment and all the possibilities for a dedicated UCN and VCN source at the ESS.
Slides here...

12 Jan 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Dr. Andreas Mooser, MPI für Kernphysik, Heidelberg
The hyperfine structure of hydrogen like ions are a unique probe to access nuclear magnetic moments and nuclear structure. Thus, while eliminating the ignorance of essential links in metrology due to insufficiently known magnetic moment, at the same time these ions provide complementary insight into the inner nucleus. The very recently started ³He experiment exploits these characteristics to provide a new standard for absolute precision magnetometry and determine the nuclear charge and current distribution of ³He. To this end, a novel four Penning trap experiment was designed and built. Using novel techniques, this system enables non demolition measurements of the nuclear quantum state and allows sympathetic laser cooling of single, spatially separated ions to sub-thermal energies [1]. In the first measurement campaign, ³He was investigated by exciting microwave transitions between the ground state hyperfine states. This enabled us to determine the nuclear g-factor, the electronic g-factor and the zero field ground state hyperfine splitting of ³He with a precision of 5*10 -10, 3*10 -10 and 2*10 -11, respectively [2]. Our measurement constitutes the first direct and most precise determination of the ³He nuclear magnetic moment. The result is of utmost relevance for absolute precision magnetometry, as it allows the use of He NMR probes as an independent new standard with much higher accuracy. In addition, the comparison to advanced theoretical calculations enables us to determine the size of the ³He nucleus with a precision of 2.4*10 -17 m. In future, we aim at a direct determination of the bare nuclear magnetic moment of ³He to be compared to the bound state result. For this measurement, it is essential to implement new methods and technology such as sympathetic laser cooling and a high precision voltage source based on Josephson junctions [3]. The latest results, status and the future prospect of the experiment will be presented. References [1] A Mooser et al., J. Phys.: Conf. Ser. 1138, 012004 (2018) [2] A. Schneider et al., Nature 606, 878 (2022) [3] A. Schneider et al., Ann. Phys. 531, 1800485 ( 2019)

16 Jan 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Cloé Girad-Carillo, Institut für Physik
Searching for the Neutrinoless double beta decay with the SuperNEMO demonstrator: installation, commissioning and sensitivity study
at Zoom

17 Jan 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Georg von Freymann, TU Kaiserslautern
Photonic quantum simulation and sensing Georg von Freymann1,2 1Physics Department and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern Landau RPTU, 67663 Kaiserslautern, Germany 2Fraunhofer Institute for Industrial Mathematics ITWM, 67663 Kaiserslautern, Germany Applications of quantum technology are highly sought-after and thus supported by public funding agencies. However, the meaning of application varies depending on who you talk to: In the physics community application often means a useful laboratory implementation, while from an industrial perspective, application means solving a measurement problem in production or even creating a saleable product. To address the physics perspective, I will discuss 3D µ-printed photonic quantum simulators based on coupled waveguide system, focusing on topological protection and Floquet (time-periodic) driving. Such experimental model systems allow for studying these phenomena under very well controlled conditions. Examples are periodic driving of topologically protected edge modes in the one-dimensional Su-Schrieffer-Heeger-chain leading to depopulation of the edge mode despite topological protection [1], periodic driving of two-dimensional honey-comb-lattices establishes topological protection in an otherwise topologically trivial model system [2], switching of topological protection via excitation with and without orbital angular momentum of light [3], and establishing higher-order topological insulators using p-orbitals of the waveguides [4]. From the industry perspective I discuss recent results for terahertz quantum-sensing with undetected photons [5] allowing to measure terahertz spectral properties with visible light only, enabling both single-shot layer thickness measurements as well as spectroscopy. [1] Z. Cherpakova, C. Jörg, et al., Limits of topological protection under local periodic driving, Light: Science&Applications 8, 63 (2019). [2] C. Jörg, et al., Dynamic defects in photonic Floquet topological insulators, New J. Phys. 19, 083003 (2017). [3] C. Jörg, et al., Artificial gauge field switching using orbital angular momentum modes in optical waveguides, Light: Science&Applications 9, 150 (2020). [4] J. Schulz, J. Noh, et al., Photonic quadrupole topological insulator using orbital-induced synthetic flux, Nature Communications 13, 6597 (2022) [5] M. Kutas et al, Terahertz Quantum Sensing, Science Advances 6, eaaz8065 (2020)

Theorie-Palaver

Institut für Physik

14:15 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Carlos Tamarit, JGU Mainz
The characteristics of the cosmic microwave background provide circumstantial evidence that the hot radiation-dominated epoch in the early universe was preceded by a period of inflationary expansion. Here, it will be shown how a measurement of the stochastic gravitational wave background can reveal the cosmic history and the physical conditions during inflation, subsequent pre- and reheating, and the beginning of the hot big bang era. This will be exemplified with a particularly well-motivated and predictive minimal extension of the Standard Model which is known to provide a complete model for particle physics -- up to the Planck scale, and for cosmology -- back to inflation.

Please note the unusual time (we start 15min later than usual)

18 Jan 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Anatael Cabrera, Paris, France
The neutrino discovery (1956), by Reines & Cowan, paved the technical ground behind the establishment of much of today’s neutrino detection. Large instrumented volumes have been achieved via a key (implicit) principle: the impeccable transparency of detector, almost regardless of detection technique.Much of that technology has yielded historical success, including several discoveries and Nobel prizes, such as that of 2015 for the discovery of the Neutrino Oscillation phenomenon leading to an important modification of the Standard Model of Particle Physics. Despite their remarkable success, much of the transparent-based technology is also known to suffer from some key limitations, even after 70 years of maturity towards perfection. The pending challenge is to be to endow detectors with powerful active background rejection while allowing large volume articulation. Indeed, poor particle identification is a long standing issue. This forces experiments to rely on expensive and cumbersome external shield (active or passive), including major overburden in underground laboratories, as the only mean to mitigate otherwise overwhelming backgrounds. In this seminar, the referent shall introduce the LiquidO technology — in final stages of demonstration — relying, for the first time, heavily on detection medium opacity. The goal is enable sub-atomic particle event-wise imaging, so event topology may be use for particle ID purposes, even in the low MeV region. The development is led by the homonymous LiquidO international academic consortium with institutions over 10 countries. While not perfect, LiquidO appears to be capable to offer several detection features that might lead to breakthrough potential in the context of both neutrino and rare decay physics. The physics potential will be briefly highlighted. Beyond its most basic demonstration, LiquidO remains a testbed context for further detection R&D, where much innovation is expected and ongoing.

19 Jan 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Giuseppe Vallone, University of Padova, Italy
Within the last two decades, Quantum Technologies have made tremendous progress, from proof of principle demonstrations to real life applications, such as Quantum Key Distribution (QKD) and Quantum Random Number Generators (QRNGs). Here, we first briefly review the basic principles of QKD and QRNGs. We then discuss the results that we have recently obtained in our group at the University of Padova towards the realization of ultra-fast and secure QRNGs and mature and efficient QKD systems. Prof. Giuseppe Vallone is an Associate Professor at University of Padua since 2019 (www.dei.unipd.it/~vallone) and co-founder and CTO of ThinkQuantum (www.thinkquantum.com), a spin-off of the Univeristy of Padua pioneering a new generation of secure communication systems based on quantum technology. His research is focused on quantum information, photonic states, quantum communication, quantum random number generators and Orbital Angular Momentum states. He has three patents and more than 130 publications in the area of quantum optics and quantum information. He is currently the coordinator of the European Project QUANGO (www.quango.eu) and the Italian Project QUASAR (quasar.dei.unipd.it).

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Weixiang Chen, JGU, Chemistry
Liquid-liquid phase separation (LLPS) has been identified as a key mechanism regulating the formation of membraneless organelles inside cells. These membraneless organelles, typically composed of DNA, RNA, protein, etc., are involved in many cellular reaction networks by forming micro-sized reactors to locally concentrate specific species or signal molecules, facilitating metabolic reactions, and thus maintaining the functionality of cells. Herein, building on an established model DNA-condensate system, we report an anomalous diffusion process of short oligonucleotide during their uptake by large DNA-condensates driven by specific binding interaction. We show that the interior dynamics of DNA-condensates can be tuned by orders of magnitude at varied salinity, while the diffusional mechanism of signal uptake simultaneously adapts from non-Fickian to Fickian type diffusion. With systematical study on such anomalous diffusion process, we have found pathway to control the velocity of the diffusional process and established a generic mechanism explaining it based on an old polymer physics concept.
at Zoom

GRK 2516 Soft Matter Seminar

Uni Mainz

15:00 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Lorena Baranda, JGU, Chemistry
DNA nanotechnology employs synthetic nucleic acid strands to design and engineer nanoscale structural and functional systems of increasing complexity that may find applications in sensing, computing, molecular transport, information processing, and catalysis. Several features make synthetic DNA a particularly appealing and advantageous biomaterial for all the applications mentioned above but more specifically for sensing. First, synthetic DNA sequences, especially if of limited length (<100 nucleotides), have highly predictable interactions and thermodynamics. Second, DNA recently became quite easy and inexpensive to synthesize. Third, DNA contains several functional groups that make it quite straightforward to modify a synthetic nucleotide sequence at both ends or internally. A variety of additional reactive groups can be introduced into DNA sequences. For sensing applications, these functional groups can be used to conjugate signaling moieties (for example, fluorophore/quencher pairs). Importantly, it is also possible to conjugate different recognition elements such as antigens to a synthetic DNA sequence, thus allowing the use of antibodies as targets to be detected with DNA-based sensors. Over my introductory talk, I will present the developed work during my PhD on DNA-based sensors and how I am applying the acquired knowledge in the field of soft colloids and synthetic cells during my postdoctoral research at Prof. Andreas Walther group.
at Zoom

20 Jan 2023

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

10:00 Uhr s.t., Newtonraum, 01-122, Staudingerweg 9

Roland Netz, Freie Universität Berlin
TBA

23 Jan 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Johannes Balz, Institut für Physik
Search for invisible Higgs-Boson decays with the ATLAS detector
at Zoom

24 Jan 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Dr. Markus Klute, KIT
„I think we have it“ – with these words, the then Director General of CERN, Rolf-Dieter Heuer, commented on July 4th, 2012 the detection of a new elementary particle at the Large Hadron Collider (LHC). The search for the Higgs boson, which had lasted almost 50 years, had reached its goal. With the discovery of the Higgs boson, a new era began at the LHC, the precise measurement of the particle's properties. With the help of these properties, conclusions can be drawn about the fundamental structure of the universe and matter. In this colloquium, I will discuss the latest result and prospects in the quest to decipher the Higgs boson.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Quentin Decant, Brussels U.
Dark matter (DM) from freeze-in or superWIMP production is well known to imprint non-cold DM signatures on cosmological observables. It will be discussed how to derive constraints from Lyman-α forest observations for both cases, based on a reinterpretation of the existing Lyman-α limits on thermal warm DM. Special emphasis is placed on the mixed scenario, where contributions from both freeze-in and superWIMP are similarly important. In this case, the imprint on cosmological observables can deviate significantly from thermal warm DM. The above will be illustrated by studying a coloured t-channel mediator DM model, in which case contributions from both freeze-in through scatterings and decays, as well as superWIMP production can be important. The entire cosmologically viable parameter space, cornered by bounds from Lyman-α observations, the LHC, and Big Bang Nucleosynthesis, will be mapped.

25 Jan 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Peter von Ballmoos, IRAP, Toulouse, France
The tentative detection of a few anti-Helium nuclei [1] is presently revitalising the discussion on the existence of baryonic antimatter in the Universe. As ”the discovery of a single anti-helium nucleus in the cosmic ray flux would definitely point toward the existence of stars and even of entire galaxies made of anti-matter” [2] it has been proposed that the anti-Helium nuclei could originate from anti-clouds or anti-stars in the solar vicinity [3]. We discuss possible entities of antimatter in the Universe that would be probed through ordinary matter, with annihilation-radiation providing indirect evidence for their presence [4]. The observations of high energy (∼ 100 MeV) gamma-rays sets limits on the fraction of nuclear antimatter contained in our local and Galactic neighbourhood. We review recent gamma-ray [5] observations that set upper limits on such emissions. [1] S. Ting, https://indico.cern.ch/event/729900, (2018) [2] P.Salati, et al., Nuclear Physics B, 70, 1-3, 492, (1999) [3] V. Poulin, et al., Phs. Rev. D 99, 023016, (2019) [4] P. von Ballmoos, Hyperfine Interact. 228, 91,, (2014) [5] S. Dupourque, et al., Phs. Rev. D 103, 083016, (2021)

SPICE-Spin+X Seminar

TUK and JGU

15:00 Uhr s.t., None

Claus Ropers, MPI for Biophysical Chemistry and University of Göttingen
Developments in ultrafast electron microscopy
at Zoom and SPICE YouTube Channel

26 Jan 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Vahid Sandoghdar, Max-Planck-Institut für die Physik des Lichts, Erlangen
Laboratory manipulation of single quantum emitters and single photons has matured to a routine procedure over the past two decades. These activities have led to new emerging topics such as optomechanical functionalities and coherent cooperative interactions among several quantum emitters. In this presentation, I discuss our efforts of the last decade in coupling molecules to high-finesse Fabry-Perot cavities and nanoscopic waveguides on a chip, demonstrating dipole-induced transparency, strong coupling and single-photon nonlinearity. Moreover, I present data on precision spectroscopy of the vibronic transitions in single molecules as well as theoretical conception of hybrid optomechanical platforms for achieving long coherence and storage times. I will also present the latest results on the coupling of two or molecules to each other via a common mode of a micro-resonator.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

11:30 Uhr s.t., Hörsaal Kernphysik

Andrey Milchev, Institute of Physical Chemistry, Bulgarian Academy of Sciences
Translocation Dynamics of Vesicles Through Narrow Pores

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

14:00 Uhr s.t., 01-122 Newton Raum

Vincent Cros, Unité Mixte de Physique CNRS, Thales, Univ. Paris-Saclay
From 2D skyrmions to 3D cocoons : nucleation, motion and electrical detection of non collinear topogical spin textures Vincent Cros Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France. In the last decade, magnetic multilayers have proven to be essential structures for creating and investigating complex, topologically non-trivial spin textures through the ability to tune their composition and properties [1-2]. Two-dimensional magnetic textures such as skyrmions (or chiral domain walls) were mostly under focus. First, I will share some of our recent results showing the skyrmion nucleation can be precisely controlled using injection of current pulses through artificial notches and show how the spin-orbit torques, responsible for the skyrmion motion, can be optimized in multilayers. More specifically, I will explain how, in atomically thin Co, the SOTs amplitudes, both for damping and field-like symmetries, varies significantly when a light element, such as Al is deposited on top of Co, surpassing the values existing in literature [3]. Then I will describe how the presence and the displacement of skyrmions can be precisely followed through a simple electrical detection. By relying on our ability to perform fully-electrical manipulation and detection of magnetic skyrmions in multilayers, I will present some recent device developments for performing a basic unconventional computation operation in hardware. Beyond the 2D skyrmions, a strong interest has emerged for more complex magnetic objects which display a non-homogeneous behavior over the vertical dimension, giving them a 3D character e.g. magnetic bobbers [4] or the recently observed hopfions [5]. In the second part of my talk, I will present our recent results on 3D spin textures, called skyrmionic cocoons [6], that have a typical ellipsoidal shape and that can be stabilized in aperiodic magnetic multilayers with a variable thickness for the ferromagnetic elements. Interestingly, these skyrmionics cocoons can coexist with more standard tubular skyrmions going through all the multilayer as evidenced by the existence of two very different contrasts in room temperature magnetic force microscopy. They can also be electrically detected using magneto-transport measurements, an interesting feature for potential applications. The presence of these novel skyrmionic textures as well as the understanding of their layer resolved chiral and topological properties have been investigated by micromagnetic simulations. Finally, I will describe how the use of x-ray holography and x-ray laminography gives a precise insight into the 3D distribution of the magnetization which demonstrate the 3D nature of skyrmionic cocoons. Financial supports from FLAG-ERA SographMEM (ANR-15-GRFL-0005), from ANR MEDYNA (ANR-20-CE42-0012), from “Investissements d’Avenir" program SPiCY (ANR-10-LABX-0035), from France 2030 government grant (ANR-22-PEPR-Electronique-EMCOM and ANR-23-PEPR-Spin) and the EU Horizon2020 Programme under FET-Proactive Grant agreement No. 824123 (SKYTOP) are acknowledged. [1] A. Fert, N. Reyren and V. Cros, Nat. Rev. Materials 2, 17031 (2017) [2] K. Everschor-Sitte et al, J. Appl. Phys. 124, 240901 (2018) [3] S. Krishnia, VC et al, arXiv:2205.08486 (2022) [4] F. Zheng et al. Nat. Nanotech., 13, 451 (2018) [5] N. Kent et al. Nat. Comm. 12, 1 (2021) [6] M. Grelier, VC et al. Nature Comm, 13, 6843 (2022)

30 Jan 2023

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

16:00 Uhr s.t., Medien-Raum (03-431)

Joo-Von Kim, CNRS, Université Paris-Saclay
Resonant dynamics and anomalous thermal diffusion of magnetic skyrmions
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Konstantin Wernli, University of Southern Denmark
In the Batalin-Vilkovisky (BV) formalism, one can define a perturbative (i.e. given by Feynman graphs and rules) partition function $Z(x_0)$ for any choice of classical background (solution to Euler-Lagrange (EL) equations) $x_0$. In some examples one can extract from $Z$ a volume form on the smooth part of the moduli space of solutions to EL equations, and compare its integral with non-perturbative approaches to quantization. I will review this construction, some results from examples in the literature and ongoing joint work with P. Mnev about the behaviour at singular points $x_0$.
at Zoom

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Peter Krämer, Institut für Physik
Search for short and long-lived axions in H -> a a -> 4 photons decays with the ATLAS experiment at the LHC
at Zoom

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

16:00 Uhr s.t., Medien-Raum (03-431)

Joo-Von Kim, Centre for Nanoscience and Nanotechnology, CNRS, Université Paris-Saclay
Magnetic skyrmions are nanoscale, chiral topological solitons which exhibit a wide variety of interesting dynamical phenomena that have solicited much interest for fundamental reasons and technological applications alike. In this talk, I will discuss some recent experimental and theoretical results on two aspects of skyrmion dynamics in ferromagnetic thin film systems. The first involves the resonant dynamics in multilayered films of [Pt/FeCoB/AlOx]20, which are found to host dense robust skyrmion lattices at room temperature with a relatively low Gilbert damping of ∼0.02 [1]. Broadband ferromagnetic resonance measurements, combined with micromagnetic simulations, reveal distinct resonant modes detected in the skyrmion lattice phase. These are found to involve localised excitations, along with skyrmion core precession emitting spin waves into uniform background with wavelengths in the 50–80 nm range. The second aspect involves thermal diffusion of skyrmions in frustrated systems under spin-orbit torques, where the helicity dynamics leads to an anomalous drift that strongly depends on the strength of the Dzyaloshinskii-Moriya interaction. Such drift processes suggest the importance of helicity coupling to spin-orbit torques and may have bearing on dipole-stabilized bubbles for which drive-dependent skyrmion Hall angles and low drift velocities have been reported. [1] T. Srivastava et al, arXiv:2111.11797 [cond-mat.mes-hall].

31 Jan 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Philipp Schmidt-Wellenburg, PSI Switzerland
An electric dipole moment (EDM) of a fundamental particle would violate time and parity symmetry and by the virtue of the CPT theorem also the combined symmetry of charge conjugation and parity inversion. Searches for EDM are generally considered highly sensitive probes for new physics and might shed light on still unresolved questions in particle physics and cosmology like the origins of matter, dark matter, and dark energy. At the Paul Scherrer Institute in Switzerland, we are setting up an experiment searching for a muon EDM with a sensitivity of 3E-21 ecm using, for the first time, the frozen-spin technique~\cite{Farley2004PRL} in a compact storage ring. This will lay the ground work for a second phase with a final precision of better than 6e-23 ecm. This staged approach to search for a non-zero muon EDM probes previously uncharted territory and tests theories of BSM physics by: i) improving the current direct experimental limit of d < 1.5E-19 ecm (CL 90%) by roughly three orders of magnitude; ii) being a complementary search for an EDM of a bare lepton; iii) being a unique test of lepton-flavor symmetries; and iv) in the case of a null result, will be a stringent limit on an otherwise very poorly constrained Wilson coefficient.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Felix Kahlhöfer, KIT
Given our detailed knowledge of the dark matter energy density in the present universe, it is of great interest to study its evolution at early times in order to understand the mechanism of dark matter production. A particularly intriguing scenario, known as freeze-in, is that dark matter particles have tiny couplings and never enter into equilibrium with the thermal bath of Standard Model particles. In this talk, I will discuss various technical challenges that arise in this scenario as a result of the high temperatures and densities in the early universe. Specifically, I will show how to consistently treat the spin statistics of relativistic quantum gases and how to accurately calculate dark matter production via the Higgs resonance. Finally, I will discuss the case of freeze-in with low reheating temperature, which may be testable through cosmological, astrophysical and laboratory observations.

01 Feb 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

CANCELED: Prof. Dr. Steen Hannestad, Univ. Aarhus, Denmark
Neutrino physics in the era of precision cosmology

02 Feb 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Stephan Schiller, Heinrich-Heine-Universität Düsseldorf, Institut für Experimentalphysik
Molecular hydrogen ions (MHI), the simplest molecules, are three-body quantum systems composed of two simple nuclei and one electron. They are of high interest for fundamental physics and metrology because they provide the missing link between the fields of mass and g-factor measurements with Penning traps and spectroscopy of hydrogen-like atoms. Basically, the new ingredients introduced by the MHI are the long-range nucleus-nucleus interaction, absent in the hydrogen atom, and the quantized motion of the nuclei. Precision spectroscopy of the MHI can thus furnish novel results: (1) on the masses of proton and deuteron (in the future, also of tritium), (2) set limits for beyond-Standard-Model (BSM) forces, (3) verify the wave character of matter, and (4) test alternative theories of quantum mechanics. This is performed by comparing or matching experimental and theoretical rotational and/or vibrational frequencies. The comparison is enhanced by the availability of several recently measured transition frequencies and recent advances in ab initio theory. An additional opportunity for probing the interactions between the particles within the MHI is the precision measurement of its hyperfine structure (HFS). Only the synthesis of the HFS of the hydrogen atom, of the deuterium atom and of the molecular hydrogen ion allows probing the physics of HFS at the finest level, resolving the issue of the uncalculable nuclear contributions. We present recent results of our spectroscopy of sympathetically cooled MHI, its results and interpretation. An outlook on near-future studies is also given.

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Swapnasopan Datta, JGU, Chemistry
Conventional chemistry deals with reactants that lead to stable molecules following a classical equilibration pathway. The same holds for classical self-assembly processes, in which non-covalent interactions lead to assembly according to thermal equilibration. There are also a number of systems that reach a metastable state momentarily, and subsequently jump to another lower energy state. In supramolecular systems, this is called pathway complexity. The propensity to transition from a metastable state to an equilibrium state is a function of the energy barrier with respect to thermal energy. This is fundamentally different from the far-from-equilibrium way living systems work, which can be achieved by employing a ‘fuel’ which drives a system to a high energy state and coupling it with an environment which can bring the system back to the original state. Keys to non-equilibrium behaviour are the mechanisms through which systems are able to extract energy from the chemical reactants (‘fuel’) that drive such processes. In our group, a fuel driven enzyme mediated reaction network was established where a ligation reaction occurs followed by a dynamic steady state, whose lifetime depends on the fuel concentration and dynamics is decided by the ratio of the ligation and restriction enzymes, and finally the restriction process dominates giving back the monomers. This is achieved in our case by using ATP as a fuel which activates a ligation enzyme leading to formation of DNA polymers which get cleaved by the restriction enzyme giving back the monomers. By tuning the interactions between these polymers, one can give rise to multivalent DNA coacervates which phase separate as a function of time and eventually vanish when the restriction step dominates. This liquid liquid phase separation (LLPS) process is fundamentally different from conventional coacervation in that it occurs as a result of interaction between polymers which are at a very high energy as opposed to thermodynamically stable phase separation. In this talk I will talk about trapping such a reaction module inside a ‘protocell’ which is a simple mimic of a real cell and explore the possibility of making a synthetic cell bottom up inside which transient LLPS might occur. For this project, we are using liposomes as cell mimics as the phospholipid bilayer which they contain closely resembles a cell.
at Zoom

03 Feb 2023

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

10:00 Uhr s.t., Newtonraum, 01-122, Staudingerweg 9

Jeetain Mittal, Texas A&M
TBA

06 Feb 2023

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., Munich, Theresienstr. 37A, R. 348

Renann Lipinski Jusinskas, Prague
In this talk I will present a worldsheet model obtained from "twisting" the target space CFT of conventional string theory. The physical spectrum becomes finite and corresponds to the massless spectrum of closed strings plus a single massive level of the open string. The underlying idea is to explore the field/string theory interface in both directions. On one hand, the goal is to generate effective field theories describing massive higher spins using worldsheet methods. Conversely, we may try to use field theory methods to obtain a systematic description of string scattering amplitudes using field theory methods.
at Zoom

07 Feb 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Dr. Tom Aumann, TU Darmstadt & GSI Darmstadt
Reactions with short-lived nuclei are key to understand the properties of neutron-rich nuclei and neutron-rich nuclear matter. In recent years, quasi-free scattering experiments have been developed and established for experiments with radioactive beams at GSI and RIKEN. The inverse kinematics of the reaction opens thereby the possibility for a complete characterisation of the final state, which results in an almost background-free measurement. Recent results with stable and radioactive beams will be discussed including the first measurement of short-range correlations in inverse kinematics, the observation of alpha clusters at the surface of heavy nuclei, as well as the observation of a correlated four-neutron state. The perspective for a precise determination of the neutron-neutron scattering length using the 6He(p,p alpha)2n reaction will be discussed as well.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Weiguang Jiang, JGU Mainz
Nuclear saturation is a key property of low-energy nuclear physics that depends on the fine details of the nuclear interaction. We develop a unified statistical framework that uses realistic nuclear forces to link the theoretical modeling of finite nuclei and infinite nuclear matter. We also construct fast and accurate emulators for nuclear-matter observables and employ an iterative history-matching approach to explore and reduce the enormous parameter domain of Delta-full chiral interactions.

08 Feb 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Julien Lesgourgues, Aachen
Cosmologists are puzzled by a tension between the results of two categories of observations, which has been growing over the past few years. This “Hubble tension” arises from contradictory indications concerning the current expansion rate of the universe. The referent will try to give a pedagogical overview of this problem, with a summary of the physical assumptions that go into the interpretation of each observation. Then, assuming that the tension persists with future data releases, he will give examples of the kind of new fundamental physics that could help solving it.
Slides here...

09 Feb 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Dr. Immanuel Bloch, Max-Planck-Institute of Quantum Physics, Garching
Quantum Simulations using Ultracold Atoms in Optical Lattices 40 years ago, Richard Feynman outlined his vision of a quantum simulator for carrying out complex calculations of physical problems. Today, his dream has become a reality and a highly active field of resarch across different platforms ranging from ultracold atoms and ions, to superconducting qubits and photons. In my lecture, I will outline how ultracold atoms in optical lattices started this vibrant and interdisciplinary research field 20 years ago and now allow probing quantum phases in- and out-of-equilibrium with fundamentally new tools and single particle resolution. In addition, I will show how fundamentally new avenues of controlling light-matter interactions can be realized based on the rich interplay of photon-mediated dipole-dipole interactions in structured subwavelength arrays of quantum emitters. In the experiments, we directly observe the cooperative subradiant response of such an ordered array of ultracold atoms. Through spatially resolved spectroscopic measurements, our experiments show that the array acts as an efficient mirror formed by only a single monolayer of a few hundred atoms. Finally, I will discuss latest experiments, where the optical properties of the entire array can be switched via a single Rydberg impurity that is deterministically prepared in the center of the array. This opens the path towards novel structured quantum light matter interfaces with unique properties in free space.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

15:00 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7,

Roberto Covino, Frankfurt Institute for Advanced Studies
Molecular self-organization driven by concerted many-body interactions produces the ordered structures that define both inanimate and living matter. Understanding the physical mechanisms that govern the formation of molecular complexes is key to controlling the assembly of nanomachines and new materials. Molecular dynamics simulations and single-molecule experiments offer the unprecedented possibility to reveal mechanisms of molecular self-organization in high resolution. However, outstanding limitations hinder their success. Machine learning and artificial intelligence promise to empower both approaches to overcome fundamental challenges. In the first part of my talk, I will present an autonomous AI that learns molecular mechanisms from computer simulations. The AI agent simulates infrequent and stochastic molecular reorganizations and progressively learns how to predict their outcome. Using symbolic regression, we distill simplified quantitative models that reveal mechanistic insight in a human-understandable form. Our innovative AI enables sampling rare events by autonomously driving many parallel simulations with minimal human intervention and aids their mechanistic interpretation. I will present applications on nucleation processes, the assembly of membrane proteins in lipid bilayers, and polymer and protein folding. In the second part of my talk, I will discuss how integrating physical modeling and AI helps extract mechanistic understanding from single-molecule force spectroscopy. While these experiments offer the possibility of measuring fundamental quantities like free energies, these measurements are often incomplete and indirect. In practice, we measure a few order parameters that are the outcome of the coupled dynamics of the molecule and the mesoscopic experimental apparatus, which could lead to estimation artifacts. I will discuss this problem as Bayesian inference and illustrate how simulation-based inference provides a powerful solution. Coupling a simulator that encodes the physics of the measuring process with density estimation using neural networks leads to accurate estimates of molecular free energies. In conclusion, integrating physics-based models and AI provides a powerful way to extract accurate quantitative information from simulations and biophysical experiments.

15 Feb 2023

SPICE-Spin+X Seminar

TUK and JGU

15:00 Uhr s.t., None

Alberta Bonanni, Johannes Kepler University
A stride down the quantum materials roadmap
at Zoom and SPICE YouTube Channel

22 Feb 2023

SPICE-Spin+X Seminar

TUK and JGU

15:00 Uhr s.t., None

Angela Wittmann, JGU
Exploring spintronics at unconventional hybrid interfaces
at Zoom and SPICE YouTube Channel

16 Mar 2023

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

14:00 Uhr s.t., 01-122 Newton Raum

Masahiro Yamashita, Department of Chemistry, Faculty of Science, Tohoku University, Sendai, Japan
Spintronics, based on the freedoms of charge and spin of the electron, is a key technology in the 21st century. Magnetic random access memory (MRAM), which uses giant magnetoresistance (GMR), has several advantages compared with electronics. Although conventional magnets composed of transition metals are normally used, in our study, we use molecule-based nano-magnets and single-molecule magnets (SMMs) to overcome “Moore`s Limitation”. SMMs are also available for quantum computer. I will talk about the molecular spin qubits for quantum computer ([1]Crystal Engineering Method, [2]g-Tensor Engineering Method, [3]Orbital Engineering Method, and [4]Molecular Technology Method) as well as high-density memory devices such as single-molecule memory device, SMMs encapsulated into SWCNT, and metallic conducting SMMs with negative magnetoresistances.

17 Apr 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Dennis Layh, Institut für Physik
MEDUSA and CALONet High-Speed Data Transmission and a Deep Learning-based Algorithm for an Upgrade of the ATLAS Trigger
at Zoom

18 Apr 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Masaki Hori, JGU Institute for Physics
Metastable antiprotonic helium is an exotic atom composed of a helium nucleus, electron, and an antiproton. It is among the hadron-antihadron systems with the longest known lifetimes. Laser light can be used to excite atomic transitions involving the antiproton orbital. By utilizing sub-Doppler two-photon laser spectroscopy and buffer gas cooling, its atomic transition frequencies were measured to ppb-scale precision. Comparisons with the results of QED calculations allowed the antiproton-to-electron mass ratio to be determined as 1836.1526734(15). The results were used to set upper limits on fifth forces between antiprotons and nucleons at atomic length scales, and on forces that may arise between an electron and antiproton mediated by hypothetical bosons. Efforts are currently underway to improve the experimental precision using CERN’s ELENA facility. We also observed narrow spectral lines of these atoms formed in superfluid helium with a surprisingly high spectral resolution of 2 parts per million. This revealed the hyperfine structure arising from the spin interaction between the antiproton and electron, despite the atom being surrounded by a dense matrix of normal atoms. Metastable pionic helium (πHe+) contains a negative pion occupying a state of n≈l-1≈17, and retains a 7 ns average lifetime. We recently used the 590 MeV ring cyclotron facility of Paul Scherrer Institute to synthesize the atoms, and irradiated them with infrared laser pulses. This induced a pionic transition within the atom and the π- being absorbed into the helium nucleus. This constitutes the first laser excitation and spectroscopy of an atom containing a meson. By improving the experimental precision, the pion mass may be determined to a high precision as in the antiproton case.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Anna Socha, Warsaw U.
According to the standard model of cosmology, the Universe at its very beginning underwent a phase of rapid expansion, followed by a reheating period. During this epoch, the energy density, initially accumulated in the coherent oscillations of the inflaton field, was injected into the visible sector, eventually setting the initial conditions for the hot Big Bang. In this talk, I will discuss perturbative production of the Standard Model (SM) particles adopting a non-standard post-inflationary scenario with a generic equation-of-state parameter \(\bar{w}\). To specify the inflaton dynamics, I will employ the \(\alpha\)-attractor T-model of inflation, such that \(\phi\) has a monomial potential \(V(\phi) \propto \phi^{2n}\) about the minimum. Moreover, I will explore the Higgs boson-induced reheating, assuming that it is achieved through a cubic inflaton-Higgs coupling \(\phi |\mathcal{H}|^2\). In the presence of such interaction, the Higgs field acquires a \(\phi\)-dependent mass which generates a vacuum expectation value that oscillates in time and breaks the electroweak gauge symmetry. Interestingly, the non-zero Higgs mass leads to a time-dependent inflaton decay rate and generates a phase-space suppression of the reheating efficiency. This, in turn, has non-trivial consequences for the reheating dynamics, modifying the evolution of the SM radiation energy density or the duration of the reheating phase. Furthermore, the implications of the non-standard reheating for the dark sector will be discussed, exemplified by the UV freeze-in dark matter model.

19 Apr 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Sebastian Ellis, Geneva University, Switzerland
Current and future Gravitational Wave (GW) observatories target the nHz to kHz frequency range. However, phenomena both within and beyond the Standard Model can give rise to GW signals above kHz. We will briefly discuss what these signals could be, before focusing on promising techniques to search for high-frequency GWs using resonant electromagnetic cavities. The technologies that have been developed to search for axion dark matter are directly transferrable to a search for GWs. Concurrent GW/axion searches are an exciting possibility.
Slides here...

20 Apr 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Dr. Fernando Lemini, ICTP (Intl. Center for Theoretical Physics), Trieste, Italy
I discuss the concept of boundary time crystals, where the continuous time-translation symmetry breaking occurs only in a macroscopic fraction of a many-body quantum system. After introducing its definition and properties, we discuss in detail a solvable model where an accurate scaling analysis can be performed. The existence of the boundary time crystals is intimately connected to the emergence of a time-periodic steady state in the thermodynamic limit of a many-body open quantum system. I will also discuss the spreading of genuine multipartite correlations (GMC's) on such phases, showing results both for the (i) the structure (orders) of GMC's among its subsystem constituents, as well as (ii) their build-up dynamics for an initially uncorrelated state.

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Yuqing Wang, JGU, Chemistry
Printing of biologically functional constructs is significant for applications in tissue engineering and regenerative medicine. However, the development of bio-ink, a printable cell-laden material, remains a major challenge due to its multifaceted demands. While printability is highly dependent on the physical properties of the material, the formation of functional tissues requires interactions between the cells and the extracellular matrix. In this work, a balance between the physical processability and cytocompatibility is achieved by using a supramolecular approach. Therefore, one supramolecular network which shows fast stress relaxation and supports cell proliferation is mixed with a second physical network that can be transformed into a chemical network by applying an external photo trigger. The interpenetrating networks obtained have improved shape fidelity while the cytocompatibility is maintained.
at Zoom

24 Apr 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Savitri Gallego, Institut für Physik
From short baseline reactor neutrino experiment to gamma-ray astrophysics
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Ed Segal, University College London
Given a Hamiltonian torus action on a symplectic manifold, Fukaya and Teleman tell us that we can relate the equivariant Fukaya category to the Fukaya category of a symplectic reduction. Yanki Lekili and I have some conjectures that extend this story - in certain special examples - to singular values of the moment map. I'll also explain the mirror symmetry picture that we use to support our conjectures, and how we interpret our claims in Teleman's framework of `topological group actions' on categories.
at Zoom

25 Apr 2023

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

PRELIMINARY DISCUSSION, Institut fuer Physik
VORBESPRECHUNG

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Gaute Hagen, Oak Ridge National Lab. Knoxville - USA
High performance computing, many-body methods with polynomial scaling, and ideas from effective-field-theory is pushing the frontier of ab-initio computations of nuclei. Here I report on advances in coupled-cluster computations of nuclei starting from chiral Hamiltonians with two- and three-nucleon forces. The ab-initio approach can now be used to address fundamental questions related to the nature of the neutrino by accurate computations of neutrino-less double beta decay and making first steps towards neutrino-nucleus scattering on relevant nuclei. Global surveys of bulk properties of medium-mass and neutron- rich nuclei from ab-initio approaches are now possible by using reference states that break rotational symmetry. These calculations have revealed systematic trends of charge radii in various isotopic chains, questioned the existence of certain magic shell closures in neutron-rich nuclei, and confrontation with data have exposed challenges for ab- initio theory. By restoring rotational symmetry, we have made predictions for the rotational structure of neutron-rich neon isotopes including 32,34Ne. In addition to entire regions of the nuclear chart now being targeted by ab-initio computations, entirely new ways to make quantified predictions are becoming possible by the development of accurate emulators of ab-initio calculations. These emulators reduce the computational cost by many orders of magnitude allowing for billions of simulations of nuclei using modest computing resources. This allows us to perform global sensitivity analysis, quantify uncertainties, and use novel statistical tools in predicting properties of nuclei. Recently we used these tools to make a quantified prediction of the neutron skin in 208Pb, and found that the neutron-skin is smaller and more precise than a recent extraction from parity-violating electron scattering but in agreement with other experimental probes. We have also used these tools to address the questions of what drives deformation in atomic nuclei and whether 28O is a bound nucleus. These developments demonstrate how realistic two- and three-nucleon forces act in atomic nuclei and allow us to make quantitative predictions across the nuclear landscape.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Fabrizio Rompineve, CERN
A population of relativistic QCD axions can be produced in the early Universe, via scatterings with Standard Model particles. This can be searched for in cosmological datasets, which therefore provide the opportunity to discover/constrain the QCD axion, independently of astrophysical and/or laboratory probes. In this talk, after reviewing the subject, I present an improved calculation of the relic abundance of such “hot” axions from scatterings with pions below the QCD crossover, as well as the resulting upper bound on the QCD axion mass. I then discuss the exciting outlook of upcoming cosmological surveys, which may probe otherwise unexplored regions of the QCD axion parameter space. I highlight the need of a non-perturbative calculation of axion production rates throughout the QCD crossover, to fully exploit the reach of such datasets.

26 Apr 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Ryan Mitchell, Indiana University, USA
Using the idea of a field guide as a template, the referent will briefly review the rapidly expanding catalog of known mesons, which are strongly interacting subatomic particles made from equal numbers of quarks and antiquarks. While most mesons can be successfully described as one quark bound to one antiquark, recent discoveries point towards the existence of new meson families. These discoveries, made at experiments such as the BESIII e+e- experiment in Beijing and the LHCb pp experiment at the LHC, offer new contexts in which to study the strong force of particle physics.
Slides here...

27 Apr 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Dr. Jack A. Devlin, Imperial College, London, UK
The toolkit of quantum technologies developed in atomic, molecular and optical physics are ideally suited to enhance the search for dark matter axions with masses above ~40 µeV. I will present an overview of a new experimental effort under construction at Imperial College, developing technologies to detect DFSZ axions with masses 120-250 µeV. We plan to use a large mode area Fabry-Perot cavity to efficiently convert axions into microwave photons. Compared to other geometries, the Fabry-Perot cavity can present a large mode volume and high Q, and can be easily tuned. To detect the microwaves, we will use an electron in a Penning trap as a single photon counter. Individual microwave absorption events will change the cyclotron state of the electron, causing measurable shifts in the trapped particle’s oscillation frequencies. This versatile device will also open other possible detection routes for alternative dark matter candidates and cosmological phenomena.

02 May 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Peter Zoller, University of Innsbruck and IQOQI - Austria
The development of atomic quantum simulation platforms has led to the creation of a new generation of programmable quantum simulators that can be scaled to large particle numbers while maintaining a certain degree of programmability. This talk reports on theory-experiment collaborative work using trapped ion platforms with up to fifty-one qubits/spins, where we develop and demonstrate quantum protocols that can address questions ranging from fundamental to practical. Examples include first observation of area law vs. volume law entanglement in ground and excited states of many-body systems, and quantum simulators acting as programable quantum sensors implementing near “optimal” entanglement-enhanced quantum metrology.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Jose Zurita, IFIC Valencia
In the last years there has been a renewed interest in the particle physics theoretical and experimental communities on the study of exotic (non-standard) signatures at colliders, including Long-Lived Particles (LLPs). In this talk I will first give a brief overview of the theoretical motivations for long-lived particles. Later I will illustrate the impact of LLPs in the current LHC physics programme, including new LHC detectors specifically hunting for LLPs (MoEDAL, FASER, SND@LHC), detector proposals under consideration (MATHUSLA, ANUBIS, FPF) and relevant upgrades to the ATLAS, CMS and LHCb experiments. Finally, I will present snapshots of novel signatures and the implications of LLP searches in the context of neutrino, axion, dark matter and Higgs physics.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

03 May 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Ida Zadeh, JGU Mainz
A conformal field theory is a physical theory which is invariant under changes in its length or energy scale. It describes the physics of boiling of water. In this talk, the referent will present how conformal field theory is used as a powerful tool to study quantum gravity. She will discuss how conformal field theories describe quantum properties of a family of black holes, just as quantum mechanics describes the Hydrogen atom.
Slides here...

04 May 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Dr. Artur Widera, TU Kaiserslautern
Excellent experimental control over quantum systems is increasingly bringing applications in quan-tum technologies within reach. In my talk, I will present our work on quantum technology applica-tions in various physical systems. Ultracold atoms have proven to be excellent platforms for studying quantum effects. In recent years, we have succeeded in introducing single Cs atoms as controlled impurities in an ultracold gas of Rb atoms. Spin-exchange collisions allow a very controlled transfer of energy quanta, and we use this transfer to operate the single atom as a machine in a magnetic field gradient. In another exper-imental setup, we address whether the significant energy differences resulting from the Pauli prin-ciple between ensembles of different fermionic and bosonic quantum statistics can be used as a novel form of energy to drive a quantum machine. Finally, I will present two new projects in the field of quantum technology. First, we are studying nanocrystals of diamond with a large number of NV centers in terms of collective effects and track-ing how the typical signatures in fluorescence lifetime and photon statistics change when larger agglomerates of nanocrystals show the transition to a bulk-like material. Second, I report on a new BMBF collaborative project, the quantum computing demonstrator pro-ject Rymax, which will simulate optimization problems from logistics and industry expressed as gra-phene problems on an array of single Yb atoms with Rydberg excitations.

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Franziska Lissel, Leibniz Institute of Polymer Research, Dresden
Triblock Copolymers – Using Nanophase Separation to Achieve Low Modulus, Elastic Deformation and Good Mobility in Polymer Semiconductors
at Zoom

08 May 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Annika Hollnagel, Institut für Physik
Search for Hidden Particles: SHiP @ECN3
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Pyry Kuusela, JGU Mainz
Supersymmetic flux vacua in Calabi-Yau compactifications are closely related to intricate number theoretic properties of the compactification manifolds. Such relations are of interest to physicists and number theorists alike: On one hand these can be used to find new, interesting flux vacuum solutions and relate physical quantities to well-studied number theoretic functions. On the other hand, physical intuition allows one to give examples of interesting number theoretic relations and obtain evidence for various conjectures. To study these relations, we present a novel method, based on symmetries of the compactification manifold, for constructing many large families of number theoretically interesting supersymmetric flux vacua. We show that the zeta functions of the compactification manifolds factorise, as expected by the celebrated modularity conjectures. The coefficients appearing in these factorisations can be associated to elliptic curves which appear in various contexts: For instance, we argue that the value of the axiodilaton field associated to the flux vacua can be identified with the modulus of these elliptic curves. We also obtain extensive evidence for the flux vacuum modularity conjecture proposed recently by Kachru, Nally, and Yang. This talk is based on arXiv:2302.03047 with Candelas, de la Ossa, and McGovern.
at Zoom

09 May 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Szymon Pustelny, University of Krakau
Thanks to its strong immunity to environmental perturbations, for many decades, molecular nuclear systems have found extensive applications in science, technology, and medicine. One of the techniques exploring these nuclear-spin systems is the technique of nuclear magnetic resonance (NMR). While typically performed under very strong magnetic fields (>1 T), recent advances in hyperpolarization methods and magnetometric techniques have led to the emergence of a technique of zero- and ultralow-field (ZULF) NMR. Operation under such unique conditions, with simple, small, and cost-efficient experimental systems, has opened up new avenues for ultraprecise spectroscopy and relaxometry, allowing for interesting applications in chemistry and biology. In physics, ZULF NMR was used for the engineering of long-lived (tens of seconds) nuclear states and the searches for physics beyond the Standard Model. Despite these applications, however, the technique is still at its early stage and many applications will be developed in future. During the colloquium, the fundamentals and distinctive features of ZULF NMR will be presented and some of its applications will be highlighted.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

10 May 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Giovanni de Lellis, Naples University, Italy
SND@LHC is a compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in a hitherto unexplored pseudo-rapidity region of 7.2 < 𝜂 < 8.4, complementary to all the other experiments at the LHC. The experiment is located 480 m downstream of IP1 in the unused TI18 tunnel. The detector is composed of a hybrid system based on an 800 kg target mass of tungsten plates, interleaved with emulsion and electronic trackers, followed downstream by a calorimeter and a muon system. The configuration allows efficiently distinguishing between all three neutrino flavours, opening a unique opportunity to probe physics of heavy flavour production at the LHC in the region that is not accessible to ATLAS, CMS and LHCb. This region is of particular interest also for future circular colliders and for predictions of very high-energy atmospheric neutrinos. The detector concept is also well suited to searching for Feebly Interacting Particles via signatures of scattering in the detector target. The first phase aims at operating the detector throughout LHC Run 3 to collect a total of 250 fb−1. The experiment has been taking data successfully during the proton physics run of 2022. We show the detector concept, design and performance as well as the first physics results.
Slides here...

15 May 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Patrick Deucher, Institut Für Physik
Plastic Scintillator Development in Mainz
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Clay Córdova, University of Chicago
We elucidate the fate of classical symmetries which suffer from abelian Adler-Bell-Jackiw anomalies. Instead of being completely destroyed, these symmetries survive as non-invertible topological global symmetry defects with worldvolume anyon degrees of freedom that couple to the bulk through a magnetic one-form global symmetry as in the fractional hall effect. These non-invertible chiral symmetries imply selection rules on correlation functions and arise in familiar models of massless quantum electrodynamics and models of axions (as well as their non- abelian generalizations)
at Zoom

16 May 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Rebecca Surman, University of Notre Dame, Indiana USA
The groundbreaking discovery of the neutron star merger event GW170817 ushered in a new era of multimessenger astrophysics. One key observation was the optical signal that accompanied GW170817, which provided the first firm proof that neutron star mergers produce heavy elements. Still, it is not known exactly which elements are produced by mergers and in what proportions. Are neutron star mergers the sole astrophysical source of the heaviest elements or do other extreme events contribute? A full understanding of neutron star mergers and their role in galactic chemical evolution requires progress in a number of areas including nuclear physics. Thousands of exotic nuclear species participate in neutron star merger nucleosynthesis, and their properties shape abundance patterns and kilonova signals. Here we discuss how nuclear physics uncertainties influence predictions of nucleosynthesis observables. We then explore the promise of experimental campaigns at rare isotope beam facilities to both reduce these uncertainties and provide insight into astrophysical environments of heavy element production.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Anne Spiering, Bohr Inst
The direct integration of Feynman integrals can be a daunting task, in particular for increasing numbers of loops and external particles. The “symbol bootstrap” has proven to be a powerful tool in the calculation of certain polylogarithmic Feynman integrals and scattering amplitudes that bypasses this direct integration. In this approach one first writes an ansatz for the symbol of the integral and then fixes its degrees of freedom by imposing known mathematical and physical properties of the final result. In this talk I will discuss a generalisation of this approach to an elliptic case: the 12-point two-loop double-box integral. The bootstrapping ansatz is obtained from an elliptic generalisation of the so-called Schubert problem, and after imposing a sufficient number of constraints on this ansatz, we obtain a compact one-line formula for the (2,2)-coproduct of the double-box integral.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

17 May 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Vera Gülpers, University of Edinburgh
Indirect high-precision searches for possible deviations from Standard Model predictions at low energies are an important tool for finding signatures of new physics. Ab-initio theoretical predictions involving the strong nuclear force at small energies are only possible using Monte Carlo methods in a numerical approach known as Lattice QCD. In recent years lattice calculations of several quantities, such as the pion decay constant, have reached a precision of O(1%), where electromagnetic effects can no longer be neglected. In this talk Vera Gülpers will discuss how electromagnetic effects can be included in lattice calculations and present results of our recent calculation of electromagnetic corrections to leptonic pion and kaon decays.
Slides here...

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

18:00 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7,

Bernhard von Vacano, BASF
PW 059721

https://trr146.uni-mainz.de/activities/

22 May 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Mathias Schott, Institut für Physik
High Precision Measurement of the Strong Coupling Constant
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

11:00 Uhr s.t., None

Kantaro Ohmori, Tokyo
The common statement that any consistent quantum gravity theory contains dynamical objects with all possible charges suggests that there are still a number of hitherto-unidentified branes in string theory. Such charges are classified by the bordism classes in the working EFT. In this talk I will describe some of those charges and then discuss plausible worldsheet descriptions of strings near the corresponding branes.
at Zoom

23 May 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Frank Cichos, University of Leipzig
Plasmonics is commonly used to confine electromagnetic waves into subwavelength noble metal structures for photonic applications. As an unwanted side effect, heat is generated locally, which is the foundation of thermoplasmonics. Besides numerous very interdisciplinary applications, such local heat generation provides unique dynamic control over microscopic objects in liquids with non-equilibrium physics. I will give two examples. First, I discuss experiments on active colloidal particles that are self-propelled by thermoplasmonic effects. Such active particles mimic the motility of living species like bacteria but lack the feedback loops that control their behavior. The optical control of plasmonic heating allows us to implement feedback loops, behavior and even learning for active particles. Using this technique, we can show that perception-reaction delays as omnipresent in living systems can be the origin of a variety of dynamical collective states that even display signatures of criticality. In a second example, I will briefly report on experiments using plasmonic heat generation to enable the control of liquids and macromolecules. Dynamic temperature fields thereby help us to study elementary processes of peptide aggregation as relevant for neurodegenerative diseases over extremely long periods of time.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Felipe Llanes Estrada, Madrid U.
The Electroweak Symmetry Breaking Sector of the Standard Model is an active field where new physics is sought. In the absence of new higher-energy particles at colliders, Effective Field Theories in terms of the Standard Model particles (longitudinal gauge and Higgs bosons) seem a natural tool. New physics could then manifest itself as new forces modifying the couplings of those particles. Should such new forces be found, they could be used to confront (falsify?) the popular SMEFT: as it is not the most general possible EFT, we have managed to produce correlations among the parameters of the embedding HEFT that can be tested if that new physics is describable by SMEFT. We have also extended HEFT via the Inverse Amplitude Method to be able to address resonances in the electroweak sector directly from the low-energy particles and eventual BSM couplings, thus maintaining agnosticism about the nature of the eventual new physics, and I will discuss the systematic uncertainties of the unitarization procedure. Based on various works, e.g. https://inspirehep.net/literature/2120028 https://inspirehep.net/literature/2154526 https://inspirehep.net/literature/1826204 https://inspirehep.net/literature/1345172 https://inspirehep.net/literature/1310013

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Anna Liedtke, Institute of Physics
Spin-Orbit Torques in the van-der Waals materials Fe3GeTe2 and Fe3-xCoxGeTe2

24 May 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Mikhail Shaposhnikov, EPF Lausanne, Switzerland
The referent will overview the problem of baryon asymmetry of the Universe and the theoretical framework within which the baryogenesis, i.e. the dynamical generation of a matter–antimatter asymmetry, can occur. He will discuss different mechanisms for baryogenesis with special emphasis to those of them that can be experimentally tested.
Slides here...

25 May 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Dr. Enno Giese, TU Darmstadt
Light pulses are an excellent tool to manipulate atoms, so that they move in superposition of different trajectories through space and time. In analogy to the concept of an optical interferometer, these branches can be brought to interference and used as sensors for gravity and other inertial forces. As such, atom interferometry has become a versatile tool technique high-precision quantum metrology, which ranges from gyroscopes to gravitational wave detection, as well as a testbed for the interface of relativity and quantum mechanics. At the same time, atoms not only possess a center-of-mass motion, but also internal degrees of freedom that are the very basis for atomic clocks. Making use of this additional property, one can in principle generate atomic clocks that move in superposition of different branches, interfere with each other, and therefore constitute a different probe of relativistic effects linked to time. This colloquium gives an introduction into the main concepts of atom interferometry and the toolbox necessary to manipulate atoms. While we explain basic examples of atom interferometers and state-of-the-art experiments, we also discuss current and ambitious proposals for high-precision tests of fundamental physics.

30 May 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Angela Wittmann, JGU Institute for Physics
Controlled manipulation of a system allows for systematic investigation of the underlying interactions and phenomena. Simultaneously, tunability also enables the development of novel materials systems and devices customized for specific applications. Here, we will focus on materials systems that conventionally have not been used as active components in spintronic devices. We will explore the impact of strain on the antiferromagnetic domain structure via magneto-elastic coupling1. Furthermore, we will delve into hybrid molecule-magnetic interfaces. Molecules offer a unique way of controlling and varying the structure at the interface making it possible to precisely tune the spin injection and diffusion by molecular design2. In particular, chirality has gained recent interest in the context of the chiral-induced spin selectivity effect3. Here, we will explore signatures of spin filtering at a non-magnetic chiral molecule-metal interface paving the path toward novel hybrid spintronics.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Christian Ecker, Frankfurt U.
According to the inflationary theory of cosmology, most elementary particles in the current universe were created during a period of reheating after inflation. In this talk I will show how to self-consistently couple the Einstein-inflaton equations to a strongly coupled quantum field theory (QFT) that is described by holography. I will then use a specific example to demonstrate that this setup leads to an inflating universe, a reheating phase and finally a universe dominated by the QFT in thermal equilibrium. This talk is based on arXiv:2302.06618.

31 May 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Robert Wilson, Colorado State University, USA
Forty years ago as an undergraduate contemplating graduate school in high energy physics, the referent declined a research assistantship to work on a neutrino experiment because neutrinos weren’t interesting … they were massless and weakly interacting so produced frustratingly few events to analyze even in massive detectors. How things have changed! The more we learn, the more we realize the importance of the most abundant known matter particle in the universe. In the decades since my naïve snubbing of this intriguing particle we have developed a well-established three-flavor paradigm that may help explain the matter-antimatter asymmetry of the universe. Yet beyond that, a few intriguing measurement “anomalies” hint at the existence of something stranger still, a neutrino that does not interact via any known forces except gravity, a sterile neutrino. Robert Wilson will give a brief overview of the results that motivated a definitive search for sterile neutrinos with a mass in the 1 eV/c2 range – the Short-Baseline Neutrino program at Fermi National Accelerator Laboratory. He will describe the physics sensitivity and the detectors that will measure the appearance of electron-type neutrinos in a muon-type neutrino beam using massive liquid argon time-projection chambers with an emphasis on the 760-ton far detector developed by the ICARUS collaboration. Operating both in Italy’s Gran Sasso underground laboratory and now at Fermilab, this detector demonstrated the viability of the technology for large-scale experiments such as the international Deep Underground Neutrino Experiment (DUNE).

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

16:00 Uhr s.t., KpH lecture room, 00-200, Johann-Joachim-Becher-Weg 45

Nico Bischoff, R+V
Hybrid event; PW: 359038

PW: 359038

01 Jun 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Matthew Baker, Maastricht University
TBA
at Zoom

06 Jun 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Susan Gardner, University of Kentucky - USA
Questions that drive searches for physics beyond the Standard Model include the physical origin of the cosmic baryon asymmetry and of dark matter. Quark dynamics, as realized through the theory of quantum chromodynamics (QCD), can appear in these studies in very different ways. In this talk, I develop these possibilities explicitly, first describing the role of QCD in ultra-sensitive searches for new physics, particularly at low energies, and then turning to how its features could be exploited in describing the undiscovered universe, along with the essential observational and experimental tests that could confirm them.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Bibhushan Shakya, DESY
The Standard Model Higgs becomes tachyonic at high energy scales according to current measurements. This unstable regime of the Higgs potential can be realized in the early Universe during high scale inflation, potentially with catastrophic consequences. In this talk, we will discuss a crucial inherent feature of such configurations that has so far remained ignored: Higgs particle production out of vacuum induced by the rapidly evolving Higgs field, which gets exponentially enhanced due to the tachyonic instability. We will discuss various theoretical and observational implications of this effect.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Dr. Olena Fedchenko, Institut für Physik / KOMET 5
Investigation of phase-transition in Mo1-x Wx Te2 using ToF-MY

07 Jun 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Alexander Gerbershagen, University of Groningen, Netherlands
The presentation covers the aspects of the use the accelerators for the hadron therapy. It includes the summary of the advantages of hadron use for radiation treatment of cancer, the technological solutions used for the beam acceleration, dose delivery and application, and an overview over the types of commercially available systems. Following that, the presentation concludes by describing the newly established the PARticle Therapy REsearch Center (PARTREC) in Groningen. Using the superconducting cyclotron AGOR and being embedded within the University Medical Center Groningen, providing proton beams of up to 190 MeV and ion beams (up to Pb) with energies up to 90 MeV/nucleon for pre-clinical research in medical physics and radiobiology.
Slides here...

12 Jun 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Tim Schneemann, Institut für Physik
SUPAX - A Superconducting Axion Search Experiment
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Medienraum (IPH, 03-431)

Apratim Chatterji, IISER-Pune, Pune
I shall present our recent results where we modify internal-topology of ring polymers (bead-spring model) to obtain localization of polymer segments within cylindrical confinement. We tried out a variety of topologies to establish the entropic principles which lead to localization of polymer segments. Two polymers in a mixed state under cylindrical confinement undergo segregation, and again topology plays an important part in determining the forces which lead to segregation and subsequent localization. We have used this understanding to predict the localization of loci (polymer segments) of bacterial DNA polymers, as the chromosome is replicating and segregating. It is known that some simple bacterial cells do not have the required machinery to separate their chromosomes within the cell. We have matched out model simulations results for two different bacterial chromosomes, moreover, our model simulation match data from two different experimental techniques ( HiC and FISH) which are complementary in spirit. I am extending our topology driven organization understanding in a variety of scenarios, some of which will be useful to understand more complex organization of chromosomes within more complex cells as well in more complex scenarios of multifork replication within the bacterial cell.

13 Jun 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Frank Stefani, Helmholz-Zentrum Dresden-Rossendorf
Magnetic fields of planets, stars and galaxies are generated by the homogeneous dynamo effect, or self-excitation, in moving electrically conducting fluids, such as liquid metals or plasmas. Once generated, magnetic fields can promote cosmic structure formation by destabilizing, via the magnetorotational instability (MRI), rotational flows that would be otherwise hydrodynamically stable. Closely related instabilities, such as the current-driven Tayler instability might be at work in the solar tachocline. For a long time, these topics had been the subject of purely theoretical and numerical research. This situation changed in 1999 when the threshold of magnetic-field self-excitation was exceeded in the two liquid sodium experiments in Riga and Karlsruhe. Since 2006, the VKS dynamo experiment in Cadarache has successfully reproduced many features of geophysical interest such as reversals and excursions. MRI related experiments were partly successful with the observation of the helical MRI and the azimuthal MRI at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), where first evidence of the current-driven Tayler instability in a liquid metal was obtained, too. In another liquid metal experiment at the Dresden High Magnetic Field laboratory (HLD) the “magic point” of coinciding Alfvén and sound speeds was reached, which is thought to play a key role for the heating of the solar corona. The lecture gives an overview about previous and future liquid metal experiments on dynamo action and magnetically triggered flow instabilities, with special focus on the precession driven liquid sodium experiment and the large-scale MRI experiment that are under construction in the framework of the DRESDYN project at HZDR. Particular emphasis is placed on generic questions such as the reversal mechanism of the geodynamo and the possibility of a planetary synchronization of the solar dynamo, on which those experiments might shed some fresh light.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Thomas Thiemann, Erlangen Nürnberg
The Hamiltonian approach to quantum gravity initiated by Bergman, Dirac, DeWitt, Komar, Wheeler et al has a long tradition and many quantum gravity programmes rest on it. While there has been progress in the past, the current theory is still not predictive because the Einstein-Hilbert Lagrangian is not even polynomial in the metric field which triggers many quantisation ambiguities. To eliminate those, renormalisation methods suggest themselves, preferrably directly in the Hamiltonian rather than the path integral language. After an introduction to those concepts, in this talk we present such a Hamiltonian renormalisation scheme which is derived from Wilson's notion of non-perturbative renormalisation of path integrals together with methods from constructive QFT. As a test we study Hamiltonian renomalisation of parametrised field theory in 2D which is a toy model for 4D quantum gravity in the sense that both theories are subject to the hypersurface deformation algebroid shared by all generally covariant field theories.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Giovanni Masciocchi, Institute of Physics
Strain control of magnetization: an opportunity for innovative magnetic sensors

14 Jun 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Seyda Ipek, Carleton University, USA
Everything around us, cookies, rocks, stars, galaxies... is made up of “matter” and not “antimatter”. We know that if antimatter comes close to matter, they annihilate each other leaving only energy behind. That we are here means there is no antimatter to annihilate with us! But what happened to the antimatter in the Universe? Where did it go? How did it disappear? Why/how did matter stay behind? The referent will talk about this mystery and possible ways around it, which requires new physics beyond the Standard Model of particle physics.
Slides here...

15 Jun 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

15:00 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Atieh Razavi, TU Darmstadt, Physics
TBA
at Zoom

20 Jun 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Dr. Simone Pirrotta, Italian Space Agency (ASI) Rome - Italy
Small satellites are nowadays extremely powerful, flexible and sustainable platforms that can be used to complement the missions usually assigned to larger spacecrafts. Modularity, standardization, intensive use of state-of-the art COTS technologies consent to prepare cheaper missions in shorter timeframes, thus allowing a more frequent access to space environment, including Cislunar and Interplanetary. The Italian Space Agency – ASI promotes, funds and coordinates the national initiatives also in this promising sector, both for national missions and within international cooperation. The first products of this effort are ArgoMoon and LICIACube, both 6U cubesats which operated during 2022 as first Italian spacecrafts beyond the Low Earth Orbit. The Light Italian Cubesat for Imaging of Asteroids - LICIACube participated in the NASA Double Asteroid Redirection Test - DART mission, the first active Planetary Defense mission; on September 26th 2022, few minutes after DART’s impact on asteroid Dimorphos, LICIACube captured unique images of the impact effects, primarily the plume of ejecta, and the not visible side of the secondary asteroid. The operations have been conducted by a national team coordinated by ASI. The design, manufacturing, testing and operations of the space and ground segment elements have been performed by the Italian firm Argotec under ASI management, while a wide scientific team supported the investigation preparation with impact modelling simulation and data analysis and interpretation, under the coordination of the National Institute of Astrophysics INAF. The engineering teams of Polytechnic of Milan and University of Bologna were in charge of trajectory design and optimization and the orbit determination and navigation, respectively. Captured images during the challenging fly-by confirmed the DART success as Planetary Defense initiative and provided scientists with highly valuable data, that allowed a first set of results to be confirmed and are currently under further analysis for scientific investigations. In fact, on October 11th 2022, NASA announced the complete success of the DART mission, confirming that the spacecraft’s impact altered Dimorphos’ orbit around Didymos by 32 minutes. Moreover, The LICIACube images show that the DART impact on Dimorphos generated a cone of ejected surface material with a large aperture angle. This plume has a complex and inhomogeneous structure, characterized by non-radial filaments, dust grains, and single and clustered boulders that allows us to deeply investigate the nature of the ejecta and the structure of Dimorphos.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Thomas Becher, Bern
In cross sections involving angular cuts, intricate patterns of enhanced higher-order corrections known as non-global logarithms arise. These corrections do not exponentiate and to resum them to all orders one has to resort to numerical techniques. The resummation of the leading non-global logarithms was achieved twenty years ago, but higher-logarithmic resummations remained elusive. In my talk, I will show how such resummation can be performed using renormalization group methods in effective field theory. I will demonstrate how the associated evolution equations can be implemented into a Monte-Carlo framework and will present first numerical results for higher-logarithmic resummations at both lepton and hadron colliders.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Kilian Leutner, Institute of Physics
Simulation and detection of topological spin structures

21 Jun 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Marcos Marino, Geneva University, Switzerland
Perturbation theory remains one of the main tools in physics, in particular in quantum theories. However, most perturbative series diverge factorially, and it is not obvious how to extract information from them. Their divergence also suggests that, in order to obtain accurate results, one might need additional non-perturbative information. The theory of resurgence has been proposed as a general framework to address these issues. In this talk the referent will give an introduction to this theory and will illustrate it with applications -old and new - in quantum mechanics and in quantum field theory.
Slides here...

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Abhishek Singharoy, Arizona State University
Molecular modeling of biomolecular assemblies exemplifies a disruptive area holding both promises and contentions. We will start with a brief story of simulating the first ever cell organelle in molecular details to find how nature has chosen survival fitness over efficiency of energy transfer as an evolutionary design (Cell, 2020). Despite such advances in exascale computing, biophysical simulation continues to grapple with handling molecular diversity. So, we will employ deep learning approaches often used in Google searches, called the inception network, to marry interaction signatures from Alphafold models and proteomics analysis with predictable patient outcomes (Cell Sys, 2022). An application will highlight how molecular modeling is used at an industrial scale to de-risk vector-based vaccines for distribution across 194 countries (Sci Adv 2021). We will conclude by seeing how transient interactions are difficult to predict, and path integrals with reinforcement learning offer a possible way to track diversity of dynamics (NeurIPS, 2022).

22 Jun 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14 Uhr c.t., IPH Lorentzraum 05-127

Prof. Dr. Sven Höfling, Technische Physik, Universität Würzburg
We will summarize recent progress made within our group on self-assembled quantum dot device development for quantum repeater and quantum computer applications. A particular emphasis will be on semiconductor quantum dots embedded in circular Bragg grating cavities. For scalability, spatially deterministic placement of quantum dots in bullseye cavities is pursued and tuning by electric and strain fields are implemented. To apply electric fields, a new device design for electrically contactable circular Bragg grating cavities in labyrinth geometry is employed. In(Ga)As/GaAs quantum dots (QDs) are very attractive candidates to confine single excitons and single spins serving as solid state qubits in a mature semiconductor platform. While these qubits can be directly manipulated by optical means, both optical and electrical excitation of the QDs can be implemented to efficiently generate single photons or entangled photon pairs on demand. Light-matter interaction in coupled quantum dot-cavity systems can be widely controlled by embedding the QDs into microcavities. In this presentation, we will summarize recent progress made within our group and plans on device development with self-assembled quantum dots intended for quantum repeater and quantum computer applications [1]. A particular emphasis will be on semiconductor quantum dots embedded in circular Bragg grating cavities [2,3]. For scalability, spatially deterministic placement of quantum dots in bullseye cavities is pursued and techniques for tuning by electric and strain fields are implemented. To apply electric fields, a new device design for electrically contactable circular Bragg grating cavities in labyrinth geometry is employed [4]. We report on the challenges experienced in obtaining high performance devices based on circular Bragg grating cavities and figures of merits achieved, outlining the prospects for these devices in quantum technology applications. We are grateful for financial support of this work by the German Federal Ministry of Education and Research (BMBF) within the projects Q.Link.X, QR.X, MHLASQU, PhotonQ and QD-E-QKD. Expert technical assistance by Silke Kuhn, Adriana Wolf and Margit Wagenbrenner is gratefully acknowledged. 1. C.-Y. Lu and J.-W. Pan, Nature Nanotechnology 16, 1294-1296 (2021) 2. J. Scheuer and A. Yariv, IEEE J. Quantum Electron. 39, 1555-1562 (2003) 3. M. Davanco, M. T. Rakher, D. Schuh, A. Badolato, and K. Srinivasan, Appl. Phys. Lett. 99, 041102 (2011) 4. Q. Buchinger, S. Betzold, S. Höfling and T. Huber-Loyola, Appl. Phys. Lett. 122, 111110 (2023)

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7,

Bettina Keller, Freie Universität Berlin
Rare-event simulations with Girsanov reweighting

26 Jun 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Jack MacDonald, Institut für Physik
First physics results from the FASER experiment
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Kai Cieliebak, Augsburg
Algebraic structures arising in string topology and Rabinowitz Floer homology
at Zoom

27 Jun 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Kate Scholberg, Duke University - USA
Coherent elastic neutrino-nucleus scattering (CEvNS) is a process in which a neutrino scatters off an entire nucleus. It is tremendously challenging to detect, due to the tiny nuclear recoil. CEvNS was measured for the first time by the COHERENT collaboration using the unique source of neutrinos at the Oak Ridge National Laboratory Spallation Neutron Source. This talk will describe the physics reach of CEvNS, as well as COHERENT's measurements, status and future plans.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Hendrik Meer, Institute of Physics
Control and manipulation of antiferromagnetic domains in insulating transition metal oxides

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Maria Anayeli Ramirez Ortiz, Milano Bicocca
The AdS3/CFT2 correspondence provides the best arena to test the holographic duality. This is because there is a better understanding of how to quantise strings on AdS3, compared with the higher dimensional cases, and the relative tractability of two-dimensional CFTs. In spite of this, little effort has been made to construct and classify supersymmetric AdS3 solutions. With a focus in their CFT interpretation, in this talk I will show you new AdS3 solutions in massive type IIA supergravity preserving small N=(4,0) supersymmetry. From the geometry, we engineer the dual CFT with well-known tools and propose a duality with a precise family of quivers. Additionally, we compute field theory and holographic central charges showing a clean matching in both descriptions.

28 Jun 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Daniel Wenz, JGU Mainz
A rich number of astrophysical and cosmological observations indicate the existence of a massive, non-luminous and non-baryonic matter component which is commonly referred to as dark matter (DM). One well motivated class of DM are weakly interacting massive particles (WIMPs) which arise naturally from several beyond-Standard-model theories. The XENON dark matter project aims for the direct detection of WIMPs utilizing the concept of a dual-phase time projection chamber (TPC), currently operating the 4th generation of XENON experiment, XENONnT, at the INFN Laboratori Nazionali del Gran Sasso underground laboratory. XENONnT was designed as a fast upgrade of its predecessor XENON1T, augmented by many new subsystems -- among them the world's first water Cherenkov neutron veto. The XENONnT TPC features a sensitive liquid xenon mass of 5.9 t and an unprecedented low background of intrinsic 85Kr and 222Rn, leading to an electronic recoil background rate of (15.8 +/- 1.3) events / t year keV in the region of interest. In this seminar we will report on the first WIMP search results with the XENONnT experiment, conducted in a blind analysis in an energy range between 3.1 keV and 60.0 keV, and an exposure of approximately 1.1 tonne-year.
Slides here...

29 Jun 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Benno Liebchen, TU Darmstadt, Physics
TBA
at Zoom

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Dr. Leif Schröder, Helmholtz Imaging + DKFZ Heidelberg
Chemical exchange processes play an important role for various soluble molecular systems with cavities. Hyperpolarized 129Xe gives insights into the underlying kinetics and structure parameters by providing a spin system that comes with several NMR spectroscopic advantages. It contributes to the understanding of synthetic molecules for binding greenhouse gases or characterizes hydrophobic pockets in naturally occurring proteins. This talk gives an overview how 129Xe is a powerful probe to explore such cavities. The nuclear spin of an inert gas is a useful “spy” that reveals, e.g., hidden states of different molecular symmetry. It also enables “spin counting” to quantify the attoliter volume in hollow protein structures. Such structures, normally used by bacteria to adjust their buoyancy in water, may one day also improve medical magnetic resonance imaging. Bacterial gas vesicles fill up with the harmless noble gas xenon according to the ideal gas law and have the potential to serve as powerful MRI contrast agents.

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

14:00 Uhr s.t., 01-122 Newton Raum

Oleksandr V. Pylypovskyi, Helmholtz-Zentrum Dresden-Rossendorf e.V.
The geometry of magnetic objects at the nanoscale plays a crucial role in their properties. Conventionally, the respective phenomena were considered for a long time as a result of sample boundaries leading, e.g., to the formation of closed-flux magnetization distributions and the interaction of magnetic solitons with notches in racetracks. However, such a simplified picture omits the topological properties and symmetries of the sample. A quantitative approach to predict magnetic responses based on the geometry of magnetic nanoarchitectures is provided by the theory of curvilinear magnetism. In this talk, we will discuss analytical approaches and some experimental validations of theoretical predictions for curvilinear nanomagnets. The local bends and twists of low-dimensional ferromagnets enable chiral and anisotropic responses stemming from the exchange interaction. For the particular sample scale, these responses are complemented by the magnetostatics-induced symmetry breaks and the respective formation of multiple magnetochiral characteristics of the magnetic textures. Antiferromagnetic nanoobjects inherit particular properties of curvilinear ferromagnets and complement them with more complex properties of the Neel order parameter and field-induced spin-reorientation transitions.

03 Jul 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Emanuel Meuser, Institut für Physik
Phase-2 Upgrades for the ATLAS hardware trigger system and MZ firmware development for L0Global
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Tony Pantev, U. Penn
Wild character varieties parametrize monodromy representations of flat meromorphic connections on compact Riemann surfaces. They are classical objects with remarkable geometric and topological properties. In the past twenty years new insights from algebraic geometry lead to precise conjectures on the topological structure and complexity of character varieties. I will recall some of these conjectures and will sketch a strategy for approaching them. In particular I will describe recent joint works with Chuang, Diaconescu, Donagi, and Nawata in which we use dualities in geometry and physics to extract cohomological invariants of wild character varieties from enumerative Calabi-Yau geometry and refined Chern-Simons invariants of torus knots.
at Zoom

04 Jul 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Paul Indelicato, University of Sarbonne - France
Quantum electrodynamics (QED) is part of the standard model and the best understood quantum field theory. Many tests exist, from free particles (electron and muon anomalous magnetic moment) to bound states. From the historical measurement of the Lamb-shift which lead to the advent of QED and field theories, many systems have been studied and compared to the most advanced calculations. One can cite hydrogen, positronium, muonium, highly charged, few electron ions[1] and exotic atoms (atoms in which the electron is replaced by a heavier particle like a muon, a pion or an antiproton). In this talk I will present a few cases of highly charged ions high-precision results (few ppm accuracy) obtained with our Double Crystal Spectrometer in Paris[2-4] for medium-Z elements, and preliminary results obtained at GSI on few-electron uranium. I will then present new ideas [5] and first demonstration results on QED tests using muonic atoms and transition-edge sensor micro-calorimeter at JPARC [6, 7], and their extension to antiprotonic atoms at ELENA in the future. Detailed comparison with QED and relativistic many-body calculations when relevant will be made. [1]Topical Review: QED tests with highly-charged ions, P. Indelicato. J. Phys. B 52, 232001 (2019). [2]High-precision measurements of n=2->n=1 transition energies and level widths in He- and Be-like Argon Ions, J. Machado, C.I. Szabo, J.P. Santos et al. Phys. Rev. A 97, 032517 (2018). [3]Reference-free measurements of the 1s 2s 2p 2P1/2,3/2 → 1s2 2s 2S1/2 and 1s 2s 2p 4P5/2 → 1s2 2s 2S1/2 transition energies and widths in lithiumlike sulfur and argon ions, J. Machado, G. Bian, N. Paul et al. Phys. Rev. A 101, 062505 (2020). [4]Absolute measurement of the relativistic magnetic dipole transition in He-like sulfur, J. Machado, N. Paul, G. Soum-Sidikov et al. Phys. Rev. A in press, (2023). [5]Testing Quantum Electrodynamics with Exotic Atoms, N. Paul, G. Bian, T. Azuma et al. Phys. Rev. Lett. 126, 173001 (2021). [6]Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays, T. Okumura, T. Azuma, D.A. Bennett et al. Phys. Rev. Lett. 127, 053001 (2021). [7]Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-ray Spectroscopy of Muonic Neon, T. Okumura, T. Azuma, D.A. Bennett et al. Phys. Rev. Lett. in press, (2023).

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Pouria Mazloumi, MPP Munich
In this talk, I will discuss different types of integrals over moduli space of punctured Riemann surfaces. First, I start with string scattering amplitudes and progress to the intersection number of twisted forms over the Riemann surface. I will discuss the equivalency between the two integrals and how this relation can be used to produce QFT (tree-level) amplitudes. In particular, I explore the double copy construction in amplitudes, which states that gravitational amplitudes can be expressed in terms of two sets of Yang-Mills amplitudes i.e.gravity=(gauge X gauge). I will motivate a formal construction of double copy in terms of the twisted cohomology and explain its relation to other forms of the double copy such as BCJ double copy and color kinematic duality. I will finish by discussing the possibility of extending this formalism into the loop level in both string and QFT amplitudes.

06 Jul 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Dr. Daniel Rodriguez, Universidad de Granada
Penning traps are used to perform motional-frequency measurements to deliver the most precise and accurate cyclotron-frequency values of many atomic/molecular ions and charged (anti)particles. By applying laser cooling, it is possible to better control those effects arising from deviations of the Penning trap from the ideal configuration. Since laser cooling can be only performed on a few ion species, a single laser-cooled (auxiliary) ion can be used to cool the target ion, forming an ordered structure along the magnetic-field axis of the Penning trap. At the University of Granada, we have built a 7-T Penning-trap platform and generated the (unbalanced) Coulomb crystals 42Ca+-40Ca+, 232Th+ -40Ca+ and 232ThO+-40Ca+, establishing the basis to perform quantum Penning-trap mass spectrometry and with prospects to explore laser-spectroscopy. In this talk, I will present the first Penning-trap eigenfrequency measurements using two-ion Coulomb crystals, from the detection of fluorescence photons, and will show the work carried out towards the final goal in our lab, including the recent upgrade of the laboratory after the installation of a new cryogen-free magnet.

07 Jul 2023

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 9

Erik Kalz and Abhinav Sharma, Leibniz-Institut für Polymerforschung Dresden & TU Dresden
The Physics of Odd Systems

10 Jul 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Florian Thomas, Institut für Physik
Neutrino Mass Sensitivity of Project 8
at Zoom

11 Jul 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Susana Cardoso de Freitas, INESC MN University of Lisboa - Portugal
Magnetic field sensors have a mature and transversal level of implementation in the market, from automotive to biomedical domains. The impressive technological progress in thin film preparation and characterization, combined with nano-microfabrication tools offer presently large spectra for device design. The materials discussed include several varieties of thin film materials combined onto multilayer stacks. In addition, the noise mechanisms (the “killing factor” that limits the MR sensor performance) will be discussed, and I will show successful strategies for improving the signal-to-noise ratio, improving the ultimate field detectable by an MR sensor. Examples where spintronic sensors are useful tools for precision sensing will be provided, including integration with microfluidics, optical and MEMS micromachined actuators. During my talk, I will show how challenging applications have identified creative solutions, requiring joint skills in transversal areas as physics, materials, electronics and mechanical engineering.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Olga Lozhkina, Institute of Physics
Domain wall propagation in soft magnetic wires with periodical width modulation

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Cristina Benso, MPIK Heidelberg
In our current understanding of the universe, the fundamental nature of one of its most abundant constituents, the dark matter (DM), is still a mystery. Among the many theorized candidates to play the role of DM, in this talk I will focus on sterile neutrinos with mass of O(keV) and in particular on their production in the early universe and phenomenology in terrestrial experiments today. The simplest mechanism able to produce sterile neutrino DM in the early universe is named Dodelson-Widrow mechanism after its inventors. Although very fascinating due to its extreme simplicity, if we assume that sterile neutrinos constitute the entire abundance of DM today this vanilla solution is, on the one hand, far from the region of the parameter space in which near future experiments will be sensitive to such particles and, on the other hand, mostly excluded by X-ray observations. After introducing the standard/vanilla scenario, I will discuss three minimal modifications to the standard scenario that change drastically the perspectives of detection of this DM candidate in the near future. They have to do with the following questions. What if before Big Bang Nucleosynthesis the universe evolved differently with respect to what is usually assumed? Should we consider the X-ray bound to be absolute or model dependent? What if active neutrinos interact among each other also with non-standard interactions?

12 Jul 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Thomas Schwetz, KIT Karlsruhe
In this talk the referent reviews the recent status of the hypothesis of sterile neutrinos with masses in the eV range, motivated by oscillation searches at short baselines. Indications for muon to electron neutrino transitions from the LSND and MiniBooNE experiments are in severe tension with constraints from disappearance experiments. Previous hints for electron neutrino disappearance at short-baseline reactor experiments are neither confirmed by recent data (among others from the STEREO experiment) nor supported by updated reactor flux determinations. However, previous indications from radio-active source experiments in gallium detectors have been recently confirmed by the BEST collaboration, which observes a neutrino-induced count rate about 20% lower than expected at about 5 sigma significance. However, an explanation in terms of sterile neutrinos is in strong tension with other constraints. If any of these anomalies is due to new physics, most likely more ingredients than sterile neutrino oscillations are required. The referent will comment on possible explanations of the gallium anomaly in terms of quantum decoherence.

13 Jul 2023

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

18:00 Uhr s.t., hybrid meeting, Minkowski Room, 05-119, Staudingerweg 7

Martin Vögele, Schrödinger
Hybrid meeting; ID: 814 7712 9515, Passcode: 008795

Time to be determined.

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Asst. Prof. Tracy Northup, Universität Innsbruck
Entanglement-based quantum networks hold out the promise of new capabilities for secure communication, distributed quantum computing, and interconnected quantum sensors. However, only a handful of elementary quantum networks have been realized to date. I will present results from our prototype network, in which two calcium ions are entangled with one another over a distance of 230 m, via a 520 m optical fiber channel linking two buildings. The ion-ion entanglement is based on ion-photon entanglement mediated by coherent Raman processes in optical cavities. I will discuss the advantages of trapped ions for quantum networks and the role that cavities can play as quantum interfaces between light and matter at network nodes. After examining the key metrics for remote entanglement, we will consider the necessary steps to extend this work to long-distance networks of entangled quantum processors.

17 Jul 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Moritz Hesping, Institut für Physik
Differential Measurement of Higgs Boson Associated Production with H-to-WW Decay at ATLAS
at Zoom

RIND seminar on Mathematical Physics and String Theory

U. Mainz, LMU Munich, U. Heidelberg, U. Vienna

16 Uhr c.t., None

Lorenz Schlechter, Utrecht U.
TBA
at Zoom

18 Jul 2023

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:15 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Olena Tkach, Institute of Physics
Recent developments in ToF momentum microscopy

Physikalisches Kolloquium

Institut für Kernphysik

16 Uhr c.t., HS KPH

Prof. Dr. Winfried Barth, GSI Helmholtzzentrum für Schwerionenforschung GmbH
Research on and with ions has been the subject of current scientific activities for some time. In particular, heavy ions with very different particle energies are of increasing interest. The provision of electrically charged "heavy" particle fluxes of high density and the acceleration of these particle beams is therefore of particular importance and has grown into an almost independent focus of research and development. In the talk, a brief outline of the past development of key technologies for accelerating heavy ions, especially in linear accelerators, will be given. The heavy ion linear accelerator at GSI in Darmstadt has to be upgraded for the future as a synchrotron-injector for highest intensities. In addition, the HElmholtz LInear ACcelerator HELIAC, a superconducting accelerator with the highest continuous wave intensities for heavy ion beams in the medium energy segment, is currently being designed and construction has already begun. These brand-new developments will also be presented. Die Forschung an und mit Ionen ist seit längere Zeit Gegenstand aktueller wissenschaftlicher Aktivitäten. Insbesondere schwere Ionen mit sehr unterschiedlicher Teilchenenergie sind dabei von zunehmendem Interesse. Die Bereitstellung elektrisch geladener "schwerer" Teilchenflüsse hoher Dichte und der Beschleunigung dieser Teilchenstrahlen kommt daher besondere Bedeutung zu und ist zu einem fast eigenständigen Schwerpunkt der Forschung und Entwicklung gewachsen. Im Vortrag soll ein kurzer Abriss der vergangenen Entwicklung der Schlüsseltechnologien zur Beschleunigung schwere Ionen insbesondere in Linear-beschleunigern gegeben werden. Der Schwerionenlinearbeschleuniger der GSI in Darmstadt muss für die Zukunft als Synchrotron-Injektor für höchste Intensitäten aufgerüstet werden. Darüber hinaus wird zurzeit mit dem HElmholtz LInear ACcelerator HELIAC ein supraleitender Beschleuniger mit höchstem Dauerstrichintensitäten für Schwerionenstrahlen im mittleren Energiesegment konzipiert und auch bereits begonnen zu bauen. Diese brandaktuellen Neuentwicklungen sollen ebenfalls dargestellt werden.

19 Jul 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Rodolfo Ferro-Hernandez, JGU Mainz
The fine structure constant is a fundamental parameter in the Standard Model, playing a crucial role in computing a wide range of observables and consistency relations. While the current error on $\Delta\alpha(M_Z)$ is at the level of $\sim10^{-4}$, future requirements, such as those of the FCC-ee/ILC, demand a reduction. In this talk, the referent presents an updated calculation of the hadronic contribution to $\Delta\alpha(M_Z)$. He will review different computational methods, such as the explicit integration in the timelike , renormalization group equations (RGE), and the euclidean split technique. The results emphasize the importance of accurately accounting for the charm quark contributions.

20 Jul 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Asst. Prof. Dylan Yost, Colorado State University
Because of atomic hydrogen’s simplicity, its energy levels can be precisely described by theory. This has made hydrogen an important atom in the development of quantum mechanics and quantum electrodynamics (QED). While one can use hydrogen spectroscopy to determine the Rydberg constant and the proton charge radius, a discrepancy of these constants determined through different transitions, or in different species, can indicate new physics. Such discrepancies currently persist between different measurements in hydrogen and muonic hydrogen. With this motivation in mind, I will discuss several precision spectroscopy measurements of hydrogen as Colorado State University including a relatively recent measurement of the hydrogen 2S-8D two-photon transition, a measurement of the hydrogen 2S hyperfine splitting, and our future plans to measure several relatively narrow 2S-nS transitions in hydrogen. If these latter measurements are successful, they could provide some of the most precise measurements of the Rydberg constant along with insight into the experimental discrepancies.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Online

Jerelle Joseph, Princeton University
Accurate models for interrogating and engineering biomolecular condensates

21 Jul 2023

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Elias Bernreuther, Fermilab
Searches for long-lived particles (LLPs) are a rapidly expanding frontier at the LHC and other collider experiments. Still, many gaps remain in the current search program, in particular for LLPs with masses at the GeV or sub-GeV scale and with very large decay lengths. In this talk, I will illustrate two different approaches to filling this gap by discussing two models of light LLPs and their associated collider signals. First, I will show that the dominant decay mode of vectorlike leptons can be a very long-lived pseudoscalar and a tau lepton and argue that the muon chambers of CMS or ATLAS are ideal places to search for this final state. Second, I will illustrate the excellent sensitivity of Belle II to light LLPs with meter-scale decay lengths using the example of displaced vertex signals from strongly interacting dark sectors.

25 Jul 2023

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Tin Sulejmanpasic, Durham U.
I will introduce a formalism for abelian lattice gauge theories called the Modified Villain Action formalism, which has been popular in recent years for constructing abelian gauge theories with correct symmetries and anomalies of their continuum counterparts. I will then show that this formalism can be used to write down a \(U(1)\) Chern-Simons theory on the lattice for even levels. The theory we construct suffers from the peculiar zero modes of the Gaussian differential operator which are infamous in the literature for plaguing the Chern-Simons theory with unphysical modes. I will show that such modes are related to a peculiar subsystem symmetry of a space-time lattice. This symmetry causes almost all Wilson loops to vanish. However Wilson loop-like operators with strip-like topology survive the pernicious symmetry and are topological, exactly like one expects in the continuum. Further the strip-like topology of the loops is a lattice realization of a well known phenomenon in continuum called the framing anomaly. I will further argue, time permitting, that the pernicious symmetry is really a form of gauge symmetry, projecting out certain states from the Hilbert space, and that it is not associated with any physical significance.

10 Aug 2023

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

14:00 Uhr s.t., 01-122 Newton Raum

Dr. Naoto Yamashita, Department of I&E Visionaries Faculty of Information Science and Electrical Engineering Kyushu University
Spin Metal-Oxide-Semiconductor Field-Effect transistor (MOSFET) is a promising device [1] that utilizes the fundamental material in electronics: silicon (Si). In 2007, the electrical injection of spin current into Si was achieved, overcoming the challenge of "conductance mismatch" [2]. Over the past decade, extensive research has been devoted to studying the transport of spin current in Si, resulting in the realization of room temperature operation [3]. In our investigations to enhance the magnetoresistance ratio, we have focused on understanding the physics of the metal/Si interface and proposed three different approaches [4-6]. Firstly, we have made progress by improving the crystal alignment between the spin source material and the tunneling barrier through moderate-temperature thermal annealing [4]. Secondly, we have demonstrated the spin-dependent Seebeck effect, a novel spin caloritronic effect, for the first time using semiconducting materials [5]. Lastly, we have achieved a significant reduction in electrical resistance at the interface by implementing ohmic contact on non-degenerate n-type Si with ferrimagnetic material, resulting in a 100-fold improvement [6]. By leveraging these technologies, we anticipate a notable improvement in the magnetoresistance ratio, bringing us closer to practical device applications. Reference [1] S. Sugahara and M. Tanaka, Appl. Phys. Lett. 84, 2307 (2004). [2] I. Appelbaum, B. Huang, and D. J. Monsma, Nature 447, 295-298 (2007). [3] T. Tahara, Y. Ando, M. Shiraishi, et al., Appl. Phys. Express 8, 113004 (2015). [4] N. Yamashita, Y. Ando, M. Shiraishi, et al., AIP Advances 10, 095021 (2020). [5] N. Yamashita, Y. Ando, M. Shiraishi, et al., Phys. Rev. Applied 9, 054002 (2018). [6] N. Yamashita, M. Shiraishi, Y. Ando, et al., Phys. Rev. Materials 6, 104405 (2022).

07 Sep 2023

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

13:30 Uhr s.t., Online

Yuichi Masubuchi, Department of Materials Physics, Nagoya University, Japan
Effect of node functionality on the fracture of polymer networks

14 Sep 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Mike Howard, Chemical Engineering, Auburn University, USA
Materials made from nanoparticles (NPs) have highly versatile applications, ranging from household products such as paint to functional materials used for catalysis and optoelectronics. The properties of such materials can be tailored through the chemistry of their NPs as well as the NP composition within the material. A common method to prepare such materials is to disperse the NPs in a solvent at a low volume fraction, then remove the solvent to assemble the NPs into a solid. For example, solvent drying from planar surfaces has been used to make abrasion- and bacteria-resistant NP coatings, while solvent drying from spherical droplets has been used to make porous supraparticles with significant internal void space that is promising for catalysis, photonics, and sorption. The mesoscopic structure of the NPs within these materials is known to depend on both properties of the NPs and the drying conditions; however, predicting it is challenging because the NP self-assembly involves confined molecular thermodynamics and nonequilibrium transport. In this seminar, I will discuss our efforts to use both particle-based simulations and continuum modeling (dynamic density functional theory) to model drying-induced assembly in colloidal suspensions. The two types of models shed different insights into the self-assembly process at different scales. Our principal finding is that solvent-mediated hydrodynamic interactions between NPs play a critical role in the drying process that must be captured to faithfully resolve the final structure in many cases. In future, we envision using these models to design NPs and drying processes to assemble them into materials with targeted compositions.
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Mike Howard, Chemical Engineering, Auburn University, USA
GRK 2516 Soft Matter Seminar

22 Sep 2023

Theorie-Palaver

Institut für Physik

Sonderseminar: 10 Uhr c.t., THEP seminar room (05-427)

Hidenori SONODA, Kobe University
I would like to explain how the construction of a Wilson action in the exact renormalization group (ERG) formalism is related to diffusion equations for the fields. By making the diffusion equations gauge covariant, we have managed to linearize the BRST invariance of U(1) gauge theories. But with YM theories, the BRST invariance remains non-linear, and we have not been able to solve the constraint. All this has been done in collaboration with Hiroshi Suzuki (Kyushu University).

Sonderseminar

25 Sep 2023

MMA 23 Conference (Sept 25th-28th)

Johannes Gutenberg-Universität Mainz, Institut für Physik

8:00 Uhr s.t., Alte Mensa, Johann-Joachim-Becher-Weg 3, 55128 Mainz

Dr. Martin Letz, SCHOTT AG
12th International Conference on Microwave Materials and their Applications (MMA23 from 25th to 29th September 2023)

04 Oct 2023

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

13:00 Uhr s.t., tba.

Paul J. Kelly, University of Twente
Phenomenological theories in spintronics are usually based upon semiclassical formulations of transport like the Boltzmann or diffusion equations that cannot easily accommodate the fundamentally quantum character of energy bands and Fermi surfaces; this is more readily done using scattering theory. The challenge for first-principles scattering theory is to describe the diffusive regime in which most experiments are performed. I sketch the developments that have allowed us to realize this goal culminating in the extraction of charge and spin currents [1] from large scale relativistic scattering calculations [2] that include temperature-induced lattice and spin disorder [3]. I illustrate our approach with a study of the temperature dependence of the spin-flip diffusion length and spin Hall angle for the bulk 5d transition metals [4]. It allowed us to evaluate the transport parameters required to describe a spin current through interfaces between two non-magnetic metals or between a non-magnetic and a ferromagnetic metal and focus on the temperature dependence of the spin memory loss that describes interface spin flipping [5]. When we use it to study the spin Hall effect in a thin Pt film, we find that we cannot recover the bulk spin-flip diffusion length without taking surface effects into account. The same approach allows us to examine the shunting of a charge current passed through a bilayer parallel to the interface [1], the Fuchs-Sondheimer suppression of charge currents by surfaces and interfaces [1] or the efficiency with which a spin or orbital Hall current is injected laterally from e.g Pt into Au or from Co or Py into Cu. Work carried out in collaboration with Rohit Nair, Max Rang, K. Gupta, R.J.H. Wesselink, R.X. Liu, Z. Yuan and E. Barati [1] R.J.H. Wesselink et al., PRB 99, 144409 (2019); R.S. Nair and P.J. Kelly, PRB 103, 195406 (2021). [2] A. A. Starikov et al., PRB 97, 214415 (2018). [3] Y. Liu et al., PRB 91, 220405 (2015). [4] R.S. Nair et al. PRL 126, 196601 (2021). [5] K. Gupta et al., PRL 124, 087702 (2020); PRB 104, 205426 (2021); PRB 106, 104401 (2022); PRB 106, 115425 (2022).

05 Oct 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Shan Jaing, Materials Science and Engineering, Iowa State University of Science and Technology, Ames, USA
The race of colloids and nanoparticles near the interface presents interesting transport phenomena and unique opportunities to understand their interactions. Stratification was observed when different species preside over the interfaces in the final dried coating structure. However, previous studies mostly focused on conventional homogeneous colloids. We have synthesized amphiphilic Janus particles and investigated their stratification behaviors. When mixed with homogeneous particles, upon drying Janus particles formed a complete and densely packed monolayer with their hydrophobic sides orienting towards air. This drastically increased the water contact angle of the dried film. Confocal study further revealed that Janus particles vigorously diffused towards interface two orders of magnitude faster than the Brownian motion. To explain these observations, we proposed a mechanism based on consideration of adsorption and surface charges. More importantly, the discovery may lead to new fundamental understanding of nanoparticle interactions near interfaces. The results also suggest a novel approach of fabricating functional surfaces using Janus particle as a coating additive.
at Zoom

09 Oct 2023

INSPIRE Seminars

Uni Mainz

Sonderseminar: 14:00 Uhr s.t., Staudingerweg 7, Room 01-327

Alexander M. Finkel’stein, The Weizmann Institute of Science (Israel) and Texas A&M University (USA)
Wave computations rely on superposition but doesn’t request for entanglement. To utilize the spin waves for fast computing and communications, one needs in controlling the spin waves. (For the wave computations, there should be many waves involved.) A feasible way to manipulate the spin-wave propagation is through the magnonic crystal. Magnonic crystal is a periodic in space modulation, which is analogues to the Bragg mirror in optics. We extended the idea to an AC-magnonic crystal, and showed how it could be used for generating and controlling many tunable “qubits” formed by pairs of mutually scattering spin waves. One can also utilize the AC magnonic crystal for the manipulation of the “qubits” via single-qubit gates of different kinds, thereby, opening new possibilities in the spin-wave computing. In collaboration with Ankang Liu, now at the MSU

Sonderseminar

23 Oct 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Bastian Keßler, Institut für Physik
Wavelength shifting fibres with high capture rate
at https://indico.him.uni-mainz.de/event/199/

24 Oct 2023

Physikalisches Kolloquium

Institut für Kernphysik

16 Uhr c.t., HS KPH

Prof. Tommaso Calarco, Forschungszentrum Juelich
Quantum optimal control has been shown to improve the performance of quantum technology devices up to their limits in terms e.g. of system size and speed of operation. I will review our recent results with a variety of quantum technology platforms, focusing in particular on ultracold atoms, and introduce our newly developed software for automatic calibration of quantum operations - the fundamental building block of next-generation quantum firmware
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Benoit Assi, Fermilab
The geometry underlying field space plays a pivotal role in governing on-shell scattering amplitudes. In this talk, we present a comprehensive geometric description of effective field theories, building upon prior work involving scalars and gauge fields, and further extending it to fermions. This novel field-space geometry not only offers a systematic reorganization but also significantly streamlines the computation of quantum loop corrections. Capitalizing on this framework, we attain the fermion loop contributions to the renormalization group equations for bosonic operators within the Standard Model Effective Field Theory, covering up to mass dimension eight.

25 Oct 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Jörg Jaeckel, Heidelberg Univ.
In this talk we start with the classical example of an oscillating cosmological field axion and axion-like particle dark matter. We will see that it is a suitable dark matter candidate, albeit one with interesting wave-like features that express themselves as coherent oscillations. We discuss existing and future probes of this type of dark matter. Following the theme of probing tiny oscillations we go beyond dark matter and even beyond particles and ask whether there could be a fundamental violation of Poincare invariance and study tests of this fundamental symmetry by looking for time-varying and oscillating effects.

26 Oct 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Dr. Alexandre Obertelli, TU Darmstadt Institut für Kernphysik
Rare isotope facilities have given access to the neutron-rich side of the nuclear landscape. In this seminar, the recent results obtained at the RIBF, RIKEN, on the structure of the most neutron-rich nuclear systems studied so far, 4n and 28O, will be presented together with the challenges faced by ab initio theory. The neutron excess in neutron-rich nuclei develop as a neutron skin or halo at the nuclear surface. The extension of neutrons at the nuclear surface remains relatively unconstrained. The new experiment PUMA (antiProton Unstable Matter Annihilation) at CERN aims at investigating the neutron to proton content of the nuclear density tail of stable and unstable nuclei by use of trapped antiprotons as a probe. The principle and status of the experiment will be given.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Bernd Jung & Gerhard Jung, Independent Scholar, Eltville, Germany & Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, 34095 Montpellier, France
We are generally interested in numerically studying the properties of soft matter. Due to limited computational resources, such studies often have to rely on coarse graining. This is the process of removing microscopic degrees of freedom to find models that are computationally much more efficient but still allow for realistic simulations of static and dynamic characteristics. While structural properties in coarse-grained models can be described and reconstructed by effective potentials, the description of dynamics is even more complex. It requires the introduction of additional dissipative and thermal forces to compensate for the systematic removal of degrees of freedom. One of the open questions in this field is how non-linearities in the underlying system influence form and dynamics of the coarse-grained model. Therefore, we investigated a system in thermal equilibrium using analytical theory, linear and non-linear projection operator formalisms, and computer simulations for a detailed analysis of the impact of such non-linearities. Our study highlights some open challenges and possible solutions in dynamic coarse graining. B. Jung, G. Jung, "Dynamic coarse-graining of linear and non-linear systems: Mori–Zwanzig formalism and beyond", J. Chem. Phys. 159, 084110 (2023), https://doi.org/10.1063/5.0165541

PW: 008795

31 Oct 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Peter Haynes, University of Cambridge
In the last 20 years or so it has been recognised that stratospheric processes have an important effect on the circulation of the troposphere and hence on weather and climate, particularly in the extratropics. The effect is now being exploited in medium range to seasonal weather prediction. The magnitude of the effect is at first surprising given that the mass of stratosphere is only about one fifth of that of the troposphere, but there are important dynamical feedback effects, both in the coupling of troposphere and stratosphere and within the troposphere itself, that amplify the tropospheric response to changes in the stratosphere. This talk will first describe the feedback effects that operate in the extratropics and then move on to consider the tropics, where significant apparent effects of the stratosphere on the troposphere have also become evident. However, the dynamics of the tropical troposphere are very different to that of the extratropical troposphere and it cannot be assumed that the same feedbacks operate in both. Some of the physical and dynamical processes that might account for observed connections between the tropical stratosphere and the tropical troposphere will be discussed.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Meet and Greet, -
-

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, JGU Mainz
VORBESPRECHUNG

02 Nov 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Dr. Jörn Müller-Quade, KIT Karlsruhe Kryptographie & Sicherheit
Classical cryptographic tasks, like key distribution, need computational assumptions and are vulnerable to attacks breaking these assumptions in the future. Classical security is not everlasting. For key distribution Quantum Cryptography offers a huge advantage, unconditionally secure protocols are possible. This success, however, could not be repeated for other important cryptographic tasks, e.g. bit commitment or coin tossing. What is more, it could even be proven that all cryptographic tasks which are sufficent for confidential computing cannot be realized with unconditional security even if a quantum channel is available. This no-go result overshadowed the research on confidential computing with quantum cryptography and the term quantum cryptography is now largely seen as a synonym for quantum key distribution. This talk shows that in spite of the no-go theorems there still are advantages of quantum cryptography over classical solutions. In particular the talk will present a yet unpublished result, that under therealistic assumption that quantum storage has a limited lifetime “everlasting security” can be achieved. I.e. computational assumptions are still needed, but the cryptographic protocol eventually becomes unconditionally secure after the quantum information used has decayed.

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Vishal Maingi, Bioengineering, Caltech
TBA
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Online

Vishal Maingi, Bioengineering, Caltech
GRK 2516 Soft Matter Seminar

PRISMA+ Colloquium

Institut für Physik

Sonderseminar: 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Robert Svoboda, UC Davis, USA
The Far Detectors for the Deep Underground Neutrino Experiment (DUNE) are currently under construction at the Sanford Underground Research Facility (SURF), set to begin operations in about four years. While designed primarily to reconstruct GeV-scale neutrino interactions to look for CP violation, some unique properties of argon make solar and supernova burst neutrino measurements particularly interesting. I will discuss why this is so interesting, why an argon detection media is so unique, and what could be the limiting backgrounds. Link to Presentation Slides: https://docs.google.com/presentation/d/1rSApQOsGt0T87olMUTKhVMMJq0kXr0G9/edit?usp=sharing&ouid=103217522426961737580&rtpof=true&sd=true

Sonderseminar

06 Nov 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Vsevolod Orekhov, Institut für Physik
Development of comprehensive analysis tools for SN neutrino detection
at https://indico.him.uni-mainz.de/event/199/

07 Nov 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

CANCELED: Dr. Axel Lindner, Deutsches Elektronen-Synchrotron (DESY)
We hereby would like to inform you that the colloquium on November 7th, 2023 has been cancelled due to an important commitment of the speaker Alex Lindner. He has been invited to a podium discussion with streaming on youtube on 7 November 19:00 h https://www.desy.de/aktuelles/oeffentliche_abendvortraege/hamburg/index_ger.html Feel free to attend it if you would like (link can be found on the above web page). We are working towards getting Alex Lindner to Mainz in the SoSe 2024.

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Encieh Erfani, JGU Mainz
In this presentation, I will elucidate the mechanisms behind Primordial Black Hole formation, discuss their potential role as candidates for dark matter, explore their significance as gravitational wave sources, and delve into the methodologies employed for their detection.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

PRELIMINARY DISCUSSION, JGU
TBA

08 Nov 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Marco Serone, SISSA, Italy
Perturbation theory is one of the most important analytical tool in quantum mechanics and quantum field theory, but it is known to give rise to divergent asymptotic series. How can we then make sense out of it? Resurgence seems to be a possible answer. After an historical detour on the study of the asymptotic behaviour of perturbation theory, we introduce basic notions of resurgence and show some application in quantum mechanics and quantum field theory.
Slides here...

09 Nov 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Dr. Hendrik Poulsen Nautrup & Dr. Sofiène Jerbi, Universität Innsbruck Institut für Theoretische Physik
Measurement-based quantum computation (MBQC) offers a fundamentally unique paradigm to design quantum algorithms. Indeed, due to the inherent randomness of quantum measurements, the natural operations in MBQC are not deterministic and unitary, but are rather augmented with probabilistic byproducts. Yet, the main algorithmic use of MBQC so far has been to completely counteract this probabilistic nature in order to simulate unitary computations expressed in the circuit model. In this talk, we are going to introduce MBQC as an ansatz for parameterized learning models that embraces this inherent randomness and treat random byproducts in MBQC as a resource for computation. We demonstrate numerically, that such models can lead to significant gains in learning performance in certain generative modeling tasks. We finish with a proposal for an experimental implementation of such an MBQC-based learning model for shuttling-based ion traps.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Hendrik Jung, FU Berlin
AI for Molecular Mechanism Discovery (aimmd)

PW: 008795

13 Nov 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Claudia Delogu, Institut für Physik
Calorimeters for particle identification
at https://indico.him.uni-mainz.de/event/199/

14 Nov 2023

Physikalisches Kolloquium

Institut für Kernphysik

16 Uhr c.t., HS KPH

Prof. Yoichiro Tanaka, Tohoku University, Japan
The digital world is producing nearly a hundred Zetta bytes of data per year and creating values for the quality of society. A huge amount of data is being stored, processed, transmitted, and then shared via large scale networked datacenters which consist of millions of data storage systems filled with perpendicular magnetic recording (PMR) hard disk drives. The PMR technology was invented by Shunichi Iwasaki in 1975 and the first commercial product was launched in 2005. Since then, the data storage has become the ever-growing foundation of the digital world and led the data-driven innovations such as bigdata AI analytics, internet of things, medical science, and even a blackhole visualization in astronomy. This lecture will provide the essential magnetics to create innovative data storage technology of PMR and the origin of the high-density recording performance which has led current recording density growth. The storage performance stands on the stacked system foundation and the building blocks are, from the base, physics of magnetics, 3D material controls of sub-nanometer in size, magnetic and electronic device design, storage device integration, and storage system architectures together with non-volatile memories to unleash the intrinsic performance. The development of new storage devices and the system requires a multi-scale approach and a right guiding principle to establish expected functions. As an extension of PMR research, the lecture will also show the prospect of future storage technology and the system architecture from the multi-scale view of the storage system development. A new computational storage system aiming at unifying computation power on data store and brain-inspired system considerations as well as the academism-industry relations to realize those systems will also be introduced.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Helena Kolešová, University of Stavanger
Taking axion inflation as an example, we study the evolution of a non-Abelian dark sector coupled to the inflaton for different choices of the confinement scale. Gravitational wave signals could be in principle generated due to a confinement phase transition or fluctuations in the thermal plasma, however, these signals might be strongly suppressed due to the presence of an early matter-dominated era. We also study the reheating of Standard Model fields and explore the possibility of glueball dark matter within this scenario.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

15 Nov 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Gianpaolo Carosi, Lawrence Livermore National Lab, USA
The axion is a hypothetical particle that may solve two problems in particle physics & cosmology, the Strong-CP problem (or why the neutron doesn’t have a measurable electric dipole moment) and the nature of dark matter. The Axion Dark Matter Experiment (ADMX), which started at Lawrence Livermore National Laboratory in the mid-1990s and has gone through a series of upgrades through the years, is the DOE Flagship search for these particles. The experiment uses tunable resonant cavities in a large static magnetic field to enhance the conversion of dark matter axions to detectable microwaves. Quantum-limited amplifiers based on superconducting Josephson Junction circuits are critical to allow the search to be sensitive enough to rapidly scan the frequencies where the axion may exist. Here I will describe the detection strategy of ADMX, the progress made so far, and outline the next phase of the experiment dubbed ADMX-Extended Frequency Range (ADMX-EFR), which aims to cover 2-4 GHz at below DFSZ sensitivity. Opportunities for physics searches beyond axions, such as potentially high frequency gravity waves, will also be discussed.
Slides here...

16 Nov 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Marcus Müller, Institute for Theoretical Physics, Uni Göttingen
Simulation studies of process-directed self-assembly
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Marcus Müller, Institute for Theoretical Physics, Uni Göttingen
GRK 2516 Soft Matter Seminar

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Dr. Wilfried Nörtershäuser, TU Darmstadt Institut für Kernphysik
Nuclear charge radii of radioactive isotopes are typically referenced to a stable nucleus in the isotopic chain through an atomic isotope shift measurement. In some cases, this can limit the uncertainty of the obtained charge radii of radioactive nuclei to the uncertainty of the reference measurements from elastic electron scattering or muonic atom spectroscopy. To overcome this limit in light mass nuclei like 10,11B, an all-optical approach for the charge radius determination purely from laser spectroscopy measurements and non-relativistic QED calculations was tested with the well-known nucleus of 12C through laser excitation of helium-like 12C4+ from the metastable 2 3S1 state with a lifetime of 21 ms to the 2 3P𝐽 states. The high-precision collinear laser spectroscopy of 12C4+ has been performed at the Collinear Apparatus for Laser Spectroscopy and Applied Physics (COALA) at at TU Darmstadt in the Institute of Nuclear Physics and meanwhile extended to 13C4+. I will give an overview of the project and present the results including the extracted all-optical nuclear charge radius of 12C. An outlook on planned measurements at COALA and a potential application on short-lived isotopes at ISOLDE will be provided. This project is supported by DFG (Project-ID 279384907 - SFB 1245).

20 Nov 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Ioana Caracas, Institut für Physik
DUNE-PRISM: An innovative technique for neutrino oscillation analysis
at https://indico.him.uni-mainz.de/event/199/

21 Nov 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Kenneth Long, Imperial College UK
The ‘Laser-hybrid Accelerator for Radiobiological Applications’, LhARA, is conceived as a novel, uniquely flexible facility dedicated to the study of radiobiology. The technologies that will be demonstrated in LhARA have the potential to allow particle-beam therapy to be delivered in a completely new regime, combining a variety of ion species in a single treatment fraction and exploiting ultra-high dose rates. LhARA will be a hybrid accelerator system in which laser interactions drive the creation of a large flux of protons or light ions that are captured using a plasma lens and formed into a beam. Serving the Ion Therapy Research Facility (ITRF), the laser-hybrid approach will allow the exploration of the vast “terra incognita” of the mechanisms by which the biological response is modulated by the physical characteristics of the beam. I will describe the motivation for LhARA, present the status of its development and summarise the programme upon which the LhARA consortium has embarked to drive a step-change in clinical capability.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Maeve Madigan, Heidelberg U.
The Standard Model Effective Field Theory (SMEFT) provides a powerful theoretical framework for interpreting subtle deviations from the Standard Model and searching for heavy new physics at the LHC. Accurate interpretations of LHC data, however, rely on the precise knowledge of the proton structure in terms of parton distribution functions (PDFs). In this seminar, I will discuss the interplay between PDFs and the search for new physics. I will showcase a scenario for the High-Luminosity LHC in which the PDFs may completely absorb such signs of new physics, thus biasing theoretical predictions and interpretations. To address this challenge, I will present a simultaneous determination of PDFs and the SMEFT using the SIMUnet methodology. This approach integrates both PDF and SMEFT determinations into a single, coherent framework, making possible an assessment of the regions of parameter space in which the interplay is most phenomenologically relevant, both at the LHC and HL-LHC.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

22 Nov 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Monica Dunford, Heidelberg Univ.
The dynamics of the Standard Model of particle physics play a central role in the properties of not only the microscopic world but also the biggest structures of our universe. The Higgs boson, for example, plays a critical part in how particles obtain their masses but also perhaps to dark matter and how our universe evolved. In this talk, the referent will focus on some key measurements that can be done with the on-going Run 3 data at the LHC and their impact on our understanding of particle physics. She will highlight how these results have connections beyond the microscopic world to dark matter, matter and anti-matter differences and beyond. In addition, she will touch upon future technology developments that will allow us to explore these connections even further.

23 Nov 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Dr. Nils Huntemann, PTB Nationales Metrologieinstitut
The 171Yb+ ion features two narrow optical transitions: an electric octupole (E3) transition as well as an electric quadrupole (E2) transition. Both transitions are suitable for the realization of an optical clock and accepted as secondary representations of the SI unit second and a composite system that relies on the spectroscopic information provided by both transitions can even provide superior clock performance. Because both transitions also show a large differential sensitivity to the fine structure constant á, its possible variations can be probed by comparing the transition frequencies at various positions in spacetime. We find improved bounds on a linear temporal drift of á, as well as its coupling to the gravitational potential of the sun, from a long-term optical clock comparison [1,2]. Additionally, the couplings of so-called ultralight bosonic dark matter (m « 1 eV/c^2) to standard model particles would lead to coherent oscillations of constants, with an oscillation frequency corresponding to the Compton frequency of the dark matter mass [3]. We conduct a broadband dark-matter search by comparing the frequency of the E3 transition to that of the E2 transition, and to that of the 1S0 ↔ 3P0 transition in 87Sr. We find no indication for significant oscillations in our experimental data. Consequently, we put limits on oscillations of the fine-structure constant and thus improve existing bounds on the scalar coupling of ultralight dark matter to photons for dark-matter masses of about 1E−24 to 1E−17 eV/c^2 [2]. Couplings to quarks and gluons can also be investigated with optical frequency ratio measurements by considering the effect an oscillating nuclear charge radius would have on electronic transitions [4]. Finally, I will report on our efforts towards clocks in which co-trapped 88Sr+ ions [5] enable even superior 171Yb+ clock performance. [1] Lange et al., Phys. Rev. Lett. 126, 011102 (2021). [2] Filzinger et al., Phys. Rev. Lett. 130, 253001 (2023). [3] Arvanitaki et al., Phys. Rev. D 91, 015015 (2015). [4] Banerjee et al., arXiv:2301.10784 (2023). [5] Steinel et al., Phys. Rev. Lett. 131, 083002 (2023).

28 Nov 2023

Physikalisches Kolloquium

Institut für Kernphysik

16 Uhr c.t., HS KPH

Prof. Eberhard Bodenschatz, MPI for Dynamics and Self-Organization, Göttingen
82 years ago, the mathematician Andrei Nikolayevich Kolmogorov postulated that a turbulent flow should have universal statistical self-similar properties. Independently, the flow researcher Ludwig Prandtl concluded similar results 4 years later. Nobel laureates Werner von Heisenberg and Carl-Friedrich von Weizsäcker and Lars Onsager each came to the same conclusion shortly thereafter. Over the years, the expected power laws have been refined, but it has not been possible to measure them at very high turbulence level necessary. Simulations of driven turbulence on the world's largest computers provide evidence of this statistical universality. These simulations are highly idealized, they live in a periodic box, and the energy is introduced globally on large scales. Experimentally, this kind of turbulent flow is not feasible. So the question is: what do experiments show? For more than 100 years, the wind tunnel has been the canonical flow regime for turbulence research. When a fluid flows through a grid at high velocity, vortices form and decay after a short time; the flow then exhibits the universal statistical properties of turbulence. Today, electronics are highly optimized and there are the smallest hotwires made with advanced nanotechnology. This also makes it possible to measure velocities on the smallest length scales. However, very high turbulence intensity is required to measure universal static properties. In the past, experiments were mainly performed with air (hence the name wind tunnel). When using air at atmospheric pressure, the wind tunnel would have to be huge in diameter to achieve extremely high turbulence intensity to test Kolmogorov like theories. This is where the Variable Density Turbulence Tunnel (VDTT) at the Max Planck Institute for Dynamics and Self-Organization comes in. Among others, I will present recent results showing that universality is found, albeit with spatially dependent logarithmic dependence of the power-law exponents.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Stefano De Angelis, IPhT, Saclay
In the first part of the seminar, I will review some recent progress made using modern on-shell techniques to understand (relativistic) EFTs and uncover hidden structures, with a particular focus on the SMEFT (from a purely on-shell construction of EFTs to selection rules in cross-section and RG equations). Motivated by this recent progress, in the second part, I will present a new on-shell formula for the matching of ultraviolet models featuring massive states onto their massless effective field theory. This formula is based on a dispersion relation in the space of complex momentum dilations to capture, in a single variable, the relevant analytic structure of scattering amplitudes at any multiplicity.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

Tobias Sparmann, JGU
TBA

29 Nov 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Laura Lopez Honorez, Univ. Brussels, Belgium
Compelling data from Cosmology tell us that more than 80% of the matter content of the universe is made of Dark Matter (DM). Yet the fundamental properties of DM is still unknown. In my talk, I will assume that DM is a particle beyond the Standard Model of Particle physics. You usually hear that DM should be cold and not hot. Yet it can be warm. The referent will discuss under which condition "non-cold" dark matter can be a good candidate to account for all the DM. In this framework, she will briefly present different mechanisms for dark matter production. She will also show that, even when dark matter interacts very feebly with visible matter, the interplay between particle physics and cosmology experiments is a key in probing the dark matter nature.
Slides here...

30 Nov 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Dijkstra, Marjolein, Computational Condensed Matter, Utrecht University
Predicting the emergent properties of a material from a microscopic description is a scientific challenge. Machine learning and reverse-engineering have opened new paradigms in the understanding and design of materials. However, this approach for the design of soft materials is highly non-trivial. The main difficulty stems from the importance of entropy, the ubiquity of multi-scale and many-body interactions, and the prevalence of non-equilibrium and active matter systems. The abundance of exotic soft-matter phases with (partial) orientation and positional order like liquid crystals, quasicrystals, plastic crystals, along with the omnipresent thermal noise, makes the classification of these states of matter using ML tools highly non-trivial. In this talk, I will address questions like: Can we use machine learning to autonomously identify local structures [1,2], detect phase transitions [1], classify phases and find the corresponding order parameters [2], can we identify the kinetic pathways for phase transformations [1], and can we use machine learning to coarse-grain our models [3,4,5]? Finally, I will show in this lecture how one can use machine learning to reverse-engineer the particle interactions to stabilize nature’s impossible phase of matter, namely quasicrystals [6]? [1] An artificial neural network reveals the nucleation mechanism of a binary colloidal AB13 crystal G.M. Coli and M. Dijkstra, ASC Nano 15, 4335-4346 (2021). [2] Classifying crystals of rounded tetrahedra and determining their order parameters using dimensionality reduction R. van Damme, G.M. Coli, R. van Roij, and M. Dijkstra, ACS Nano 14, 15144-15153 (2020). [3] Machine learning many-body potentials for colloidal systems G. Campos-Villalobos, E. Boattini, L. Filion and M. Dijkstra, The Journal of Chemical Physics 155 (17), 174902 (2021). [4] Machine-learning effective many-body potentials for anisotropic particles using orientation-dependent symmetry functions G. Campos-Villalobos, G. Giunta, S. Marín-Aguilar and M. Dijkstra, The Journal of Chemical Physics 157 (2), 024902 (2022). [5] Coarse-Grained Many-Body Potentials of Ligand-Stabilized Nanoparticles from Machine-Learned Mean Forces G. Giunta, G. Campos-Villalobos, and M. Dijkstra, ACS Nano (2023). [6] Inverse design of soft materials via a deep learning–based evolutionary strategy G.M. Coli, E. Boattini, L. Filion, and M. Dijkstra, Science Advances 8 (3), eabj6731 (2022).
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Marjolein Dijkstra, Computational Condensed Matter, Utrecht University
GRK 2516 Soft Matter Seminar

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Dr. Catalina Curceanu, INFN, Rom/Italy
We are experimentally investigating possible departures from the standard quantum mechanics’ predictions at the Gran Sasso underground laboratory in Italy. In particular, with refined radiation detectors, we are searching signals predicted by the dynamical collapse models (spontaneous emission of radiation) which were proposed to solve the “measurement problem” in quantum physics, and signals indicating a possible violation of the Pauli Exclusion Principle. I shall discuss our recent results which ruled out the natural parameter-free version of the gravity-related collapse model. I shall then present more generic results on testing CSL (Continuous Spontaneous Localization) collapse models and discuss future perspectives. Finally, I shall present the VIP experiment, with which we search for possible violations of the Pauli Exclusion Principle manifested as “impossible” atomic transitions, and muse about the impact of this research in relation to Quantum Gravity models.

01 Dec 2023

THEP Journal Club

Institut für Physik

12:30 Uhr s.t., Minkowski Raum, Staudinger Weg 7, 05-119

Anke Biekötter, JGU Mainz
SMEFT Analyses for New Physics (TBA)

05 Dec 2023

Physikalisches Kolloquium

Institut für Kernphysik

16 Uhr c.t., HS KPH

Dr. Urmi Ninad, TU Berlin
Statistical inference aims to fit observed data into a model that explains the data and is able to make predictions. However, as we are repeatedly told, ‘correlation does not imply causation’, therefore robust prediction and reasoning about underlying processes governing the data distribution cannot be done by relying on observed statistical dependences alone. Causal reasoning aims to formalise the setting under which causal, rather than merely statistical, relationships can be inferred from observed data, thereby making the learned model more indicative of the true underlying process. In the last decade, the field of causal inference has gained immense popularity in the statistics and machine learning communities to develop and utilise this framework on the one hand, and in application domains such as economics, genetics and climate to use causal algorithms to practical problems of interest on the other hand. In this talk, I will lay the foundations of causal inference, explain the various approaches to do causal inference that have emerged in the recent years, and close the talk with examples of application of the causality framework to climate science.
Slides here...

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Maura Ramirez Quezada, JGU Mainz
In this talk, I'll explore the potential of using white dwarfs as cosmic laboratories to investigate hidden interactions beyond the Standard Model. My focus will be on the cooling process of white dwarfs, specifically through neutrino emission, and investigate the impact of a dark photon in a three-portal model on the neutrino emission during white dwarf cooling.

06 Dec 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Dr. Haakon Andresen, Univ. Stockholm, Sweden
The referent will give a broad overview of current core-collapse supernova theory and highlight important challenges for the future. Currently, numerical simulations produce successful explosion, but this is only the first required step in order to understand the role of core-collapse supernovae in the wider astrophysical and cosmological picture. He will discuss the underlying uncertainties in the input physics, such as neutrino transport and stellar evolution. The refernent will also summarize the current predictions for the gravitational waves and neutrino signals expected from core-collapse supernovae.

07 Dec 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Dr.-Ing. Steffen Kurth, Fraunhofer Institut for Electronic Nano Systems ENAS
The ion trap chip is considered to be the heart of quantum computing based on trapped ions. An ideal case is to have available a devices with all sub-components that are necessary for the operation in a small package. First approaches to fabricated integrated miniaturized ion traps are followed by different groups worldwide. Latest directions are to combine multiple registers, that are connected to each other, to use micro optical components such as micro lenses or even photonic integrated circuits for coupling laser radiation to the ions, to integrate photo detectors (e.g. single photon avalanche diodes) close to or within the ion trap chip. The integration of electronic components (e.g. digital/analog-converters) to provide the electric potentials for the trap electrodes is a further goal that becomes an enabler for integrated ion traps with a higher number of registers. This talk will show how wafer level micro technologies contribute to the above described target. It starts with the vision of an integrated ion trap. Wafer level technologies for fabricating of the different layers are discussed. It covers different material deposition procedures and etching. A next section is about optical sub-components and their manufacturing procedures. Furthermore, a broad variety of assembly technologies and of ways for electric signal routing and connecting is shown with examples.

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Minkowski Room, 05-119, Staudingerweg 7

Achim Klenke, JGU, Chemistry
Mean Number of Visible Confetti

PW: 146146

Theorie-Palaver

Institut für Physik

10:30 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Kristina Giesel, FAU Erlangen
Accessing the physical sector in models of quantum gravity is on the one hand a challenge, but on the other hand also an important step to be able to analyse and test such models. One way to complete the quantisation programme in loop quantum gravity is to choose dynamical reference systems so-called matter or geometric clocks for which Dirac observables can be constructed in the framework of the relational formalism. The quantisation step then consists in finding representations for the corresponding algebra of Dirac observables that allow one to quantise the dynamics as well. In this way, one obtains an observer-dependent quantum field theory. We will give a brief overview of the existing models and discuss their similarities and differences. Finally, we will discuss examples for investigating some physical properties of models formulated with a particular choice of clocks in cosmology and open quantum systems in which gravitationally induced decoherence is present.

11 Dec 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Chen Wang, Institut für Physik
Precision Measurements of the effective weak-mixing angle and the W-boson mass
at https://indico.him.uni-mainz.de/event/199/

12 Dec 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

No Colloquium, ---
(Lecture Hall is occupied)

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Gael Finauri, TU München
Light-cone distribution amplitudes (LCDAs) frequently arise in factorization theorems involving light and heavy mesons. The QCD LCDA for heavy mesons includes short-distance physics at energy scales of the heavy quark mass. In this talk I will explain how to achieve the separation of this perturbative scale from the purely hadronic effects by expressing the QCD LCDA as a convolution of a perturbative « jet » function with the universal, quark-mass independent HQET LCDA. This factorization allows to efficiently resum large logarithms between Lambda QCD and m_Q as well as between m_Q and the scale of the hard process in the production of boosted heavy mesons at colliders. As an application I will present updated theoretical predictions for the brancing ratio of W -> B \gamma.

13 Dec 2023

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

Prof. Dr. Elina Fuchs, Univ. Hannover
New Physics Searches in the Spectra of Atoms and Ions

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)

JGU

13:00 Uhr s.t., 01-122 Newton Raum

Dr. Jun'ichi Ieda, Japan Atomic Energy Agency (JAEA)
Emergent inductance appears universally when magnetization dynamics is coupled with conduction electrons based on a sequential action of spin torque and spinmotive force effects under ac currents. An original version of the emergent inductor using > a spiral magnet[1-4] can be extended to include the spin-orbit coupling effects[5,6]. A striking common feature among emergent inductors is their size dependence of the effect; the inductance is inversely proportional to the sample cross-sectional area, opening > a way for integrating an inductor element into nanocircuits. > > 1. Nagaosa, N. “Emergent inductor by spiral magnets,” Jpn. J. Appl. Phys., Vol. 58, 120909, 2019. > 2. Yokouchi, T. et al., “Emergent electromagnetic induction in a helical-spin magnet,” Nature, Vol. 586, 232-236, 2020. > 3. Ieda, J. and Y. Yamane, “Intrinsic and extrinsic tunability of Rashba spin-orbit coupled emergent inductors,” Phys. Rev. B, Vol. 103,. L100402, 2021. > 4. Kitaori, A. et al., “Emergent electromagnetic induction beyond room temperature,” Proc. Natl. Acad. Sci. U.S.A., Vol. 118, e2105422118, 2021. > 5. Yamane, Y., S. Fukami, and J. Ieda, “Theory of emergent inductance with spin-orbit coupling effects,” Phys. Rev. Lett., Vol. 128, 147201, 2022. > 6. Araki, Y. and J. Ieda, “Emergence of inductance and capacitance from topological electromagnetism,” J. Phys. Soc. Jpn., Vol. 92, 074705, 2023.

SFB Sonderseminar

14 Dec 2023

GRK 2516 Soft Matter Seminar

Uni Mainz

17:00 Uhr s.t., Lorentz Room, 05-127, Staudingerweg 7

Florian Mast, JGU, Chemistry
Improving electrochemical reductions: finding the right supporting electrolyte through principal component analysis
at Zoom

Seminar über Theorie der kondensierten Materie / TRR146 Seminar

F. Schmid / G. Settanni / P. Virnau / L. Stelzl

14:30 Uhr s.t., Lorentz Room, 05-127, Staudingerweg 7

Florian Mast, JGU, Chemistry
GRK 2516 Soft Matter Seminar – Improving electrochemical reductions: finding the right supporting electrolyte through principal component analysis

18 Dec 2023

Seminar about Experimental Particle and Astroparticle Physics (ETAP)

Institut für Physik

12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum

Savitri Gallego, Institut für Physik
The Compton Spectrometer and Imager (COSI)
at https://indico.him.uni-mainz.de/event/199/

19 Dec 2023

Physikalisches Kolloquium

Institut für Kernphysik

16:15 Uhr s.t., HS KPH

Prof. Marialuisa Aliotta, University of Edinburgh
The Laboratory for Underground Nuclear Astrophysics (LUNA), located under 1.4km of rock under the Gran Sasso Mountain in central Italy, provides an ideal location for nuclear reaction studies of astrophysical interest. Thanks to its million-fold reduction in cosmic-induced background, LUNA affords unique opportunities to push reaction measurements to the lowest accessible energies. For over 30 years, the LUNA collaboration has thus pioneered studies of nuclear burning processes (pp-chain, CNO-, NeNa- and AlMg-cycles) directly at the relevant astrophysical energies, often for the first time [1]. In some cases, these efforts have led to remarkable results, such as for example the increased age of the universe, and have translated into a better understanding of stellar nucleosynthesis and the chemical evolution of our galaxy. In my talk, I will review some of the major highlights of LUNA’s activity and present exciting new opportunities for upcoming studies of helium- and carbon-burning reactions at the recently installed 3.5MV accelerator. [1] M. Aliotta, A. Boeltzig, R. Depalo, G. Gyurky, Ann. Rev. of Nucl. Part. Sci. 72 (2022) 177-204 [2] G. Imbriani, et al. A&A 420, 625–629 (2004)
Slides here...

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12:00 Uhr s.t., Newton-Raum, Staudingerweg 9, 1. Stock, Raum 122 (Nebengebäude)

TBA, TBA
TBA

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Andrea Sanfilippo, TU München
The description of light and massless scalar fields in an inflationary spacetime is of phenomenological interest, as they provide compelling candidates for the inflaton field. During most of the inflationary epoch, the spacetime can be approximated by the de Sitter spacetime, and the observables of interest are in-in correlation functions of fields in de Sitter space, evaluated at late times. However, the computation of these quantities is challenging, particularly when loop corrections are taken into account. In this talk, I will discuss the recently proposed Soft de Sitter Effective Theory (SdSET) as an avenue to address these difficulties. I will then show how the Method of Regions can be used as a powerful tool to construct the late-time expansion of in-in correlators, as well as to gain further insight into the structure of SdSET.

21 Dec 2023

Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)

Institut für Physik

14:00 Uhr s.t., IPH Lorentzraum 05-127

Prof. Jörg Pretz, Forschungszentrum Jülich
Electric Dipole Moments (EDMs) of elementary particles, including hadrons, are considered as one of the most powerful tool to study CP-violation beyond the Standard Model. Such CP-violating mechanisms are searched for to explain the dominance of matter over anti-matter in our universe. Hypothetical dark matter particles, like axions or axion-like-particles, induce an oscillating EDM. EDMs of charged particles can be measured in storage rings. Due to an EDM, the spin vector will experience a torque resulting in a change of the original spin direction which can be determined with the help of a polarimeter. Although the principle of the measurement is simple, the smallness of the expected effect makes this a challenging experiment requiring new developments in various experimental areas. The talk will focus on first results obtained at the Cooler Synchrotron COSY at Forschungszentrum Jülich and will also discuss future plans.

Seminar Festkörper- und Grenzflächenphysik KOMET - experimentell

Institut für Physik

12 Uhr c.t., Medienraum, Staudingerweg 7, 3. Stock, Raum 03-431

David Anthofer, JGU Mainz
Probing spin-orbit coupling at molecule/metal thin-film interfaces