Semesterübersicht Sommersemester 2024
Wintersemester 2023/2024 - Sommersemester 2024 - Wintersemester 2024/2025
16 Apr 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Ulrich Stroth, Max Planck Institute for Plasma Physics, Garching | |
In times of a shift towards a low CO2 energy supply and boosted by the recent success of laser fusion, the advantages of nuclear fusion in general have come into the focus of politics and private investors as an attractive energy source. This talk introduces the concept of magnetic fusion and outlines the path to a fusion reactor. The perspectives of magnetic fusion will be compared with those of laser fusion and the concepts of startups. The role of plasmas, in which energy is obtained from the fusion of hydrogen isotopes, and their physical properties are explained. Slides here... | |
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Theorie-Palaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) |
| Julio Virrueta, Jena U. | |
I will discuss the real-time dynamics of metric perturbations around the AdS black hole and argue that the dynamic of these modes is captured by a set of designer scalars in the background geometry. Using these results I will obtain the real-time Gaussian effective action, which includes both the retarded response and the associated stochastic fluctuations. Finally, I will discuss extensions beyond linear response. | |
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17 Apr 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Koichi Hamaguchi, Univ./IPMU Tokyo, Japan | |
Supernova-Scope for the Direct Search of Supernova Axions | |
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18 Apr 2024
Seminar über Theorie der kondensierten Materie / TRR146 Seminar
F. Schmid / G. Settanni / P. Virnau / L. Stelzl 14:30 Uhr s.t., Minkowski-Raum, 05-119, Staudingerweg 7 |
| Felix Höfling, Freie Universität Berlin | |
Emergent phenomena in flowing matter | |
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Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14 Uhr c.t., IPH Lorentzraum 05-127 |
| Dr. Felix Tennie, Imperial College, London, UK | |
Nonlinear differential equations are ubiquitous in Physics, Engineering, Chemistry, Materials Science, and various other subjects. Numerical integration often requires resources exceeding current classical supercomputers. Quantum computing presents a fundamentally different computing paradigm. Quantum algorithms have a proven scaling advantage in many linear tasks such as Fourier transformation, matrix inversion, SVD, to name but a few. Yet, due to the linear evolution of quantum systems, integrating nonlinear dynamics on quantum computers is hard. In this talk I will present different approaches for integrating nonlinear differential equations on quantum computers, and will discuss their suitability for different types of quantum hardware. | |
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22 Apr 2024
Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum |
| Annika Stein, Institut für Physik | |
Novel Jet Flavour Tagging Algorithms exploiting Adversarial Deep Learning Techniques | |
| at https://indico.him.uni-mainz.de/event/199/ | |
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23 Apr 2024
Theorie-Palaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) |
| Yann Gouttenoire, Tel Aviv U. | |
Cosmological first-order phase transitions are said to be strongly supercooled when the nucleation temperature is much smaller than the critical temperature. The phase transition takes place slowly and the probability distribution of bubble nucleation times is maximally spread. Hubble patches which get percolated later than the average are hotter than the background after reheating and potentially collapse into primordial black holes (PBHs). I will give a review of this PBHs formation mechanism and of its most recent developments. | |
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24 Apr 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Bastian Märkisch, TU München | |
Neutron Beta Decay with Perkeo III and Perc | |
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aktuell
25 Apr 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14 Uhr c.t., IPH Lorentzraum 05-127 |
| Prof. Dr. Ralf Röhlsberger, DESY, Hamburg | |
Using the high-intensity radiation of the European X-ray Free-Electron Laser, we recently succeeded to excite the sharpest atomic transition in the hard X-ray range, the 12.4 keV nuclear resonance of the stable isotope Scandium-45 [1].
With its extremely narrow natural linewidth of 1.4 femto-eV, it opens not only new possibilities for the development of a nuclear clock, but also for research linked to the foundations of physics, such as time variations of the fundamental constants, the search for dark matter as well as probing the foundations of relativity theory.
Furthermore, our experiment demonstrates the great potential of self-seeding X-ray lasers with high pulse rates as a promising platform for the spectroscopy of extremely narrow-band nuclear resonances.
The next steps towards a nuclear clock based on Scandium-45 require a further increase of the spectral photon flux using improved X-ray laser sources at 12.4 keV and the development of frequency combs reaching up to this energy.
[1] Yuri Shvyd’ko et al., Nature 622, 471 (2023) | |
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zukünftige Termine
26 Apr 2024
Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)
JGU 12:00 Uhr s.t., Media Room |
| Kilian Leutner and Thomas Winkler, JGU Mainz | |
This Friday, the 26th, from 12 to 2 pm, Kilian Leutner and Thomas Winkler will give a test run of the "Intermag 2024 Hands-on session: AI in magnetism."
We will give an introductory talk (~30 minutes) about AI in magnetism and more concrete information about our recent project: "AI-accelerated detection of spin structures in Kerr-microscopy data."
Afterward, we will ask you to open your laptops and participate actively in the AI revolution. We will guide you through our repository. The goal is that participants can infer data and even train models on their own at the end of the session.
If you are interested, feel free to have a look at our paper and official repository:
Paper: Labrie-Boulay et al., Phys. Rev. Appl. 21, 014014 (2024): https://doi.org/10.1103/PhysRevApplied.21.014014
Repository (v2.0): Winkler et al., Zenodo repository: https://doi.org/10.5281/zenodo.10997175
If you would like to join, please send an email to Kilian Leutner ( kileutne@students.uni-mainz.de ) by Thursday. Kilian Leutner will eventually send around links for a smaller data repository, install instructions this week for the session.
You can participate in this session at the Physics building in Mainz in the “Medienraum” (03-431), or you can access the session via Teams using the following link: https://teams.microsoft.com/l/meetup-join/19%3ameeting_MTRhNjI4ZWYtNDkyMC00YzQ1LWIyNzgtMzkxNjAzYjNjYjY2%40thread.v2/0?context=%7b%22Tid%22%3a%2251aa2b30-c9fa-40db-b91a-3a53a8a08d85%22%2c%22Oid%22%3a%22e50b859d-212d-4ce0-b8ca-82e26bd02e43%22%7d .
(As this is a test talk, we are also happy about some feedback) | |
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Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDyn-Seminar)
JGU 12:00 Uhr s.t., Media Room |
| Kilian Leutner and Thomas Winkler, JGU Mainz | |
This Friday, the 26th, from 12 to 2 pm, Kilian Leutner and Thomas Winkler will give a test run of the "Intermag 2024 Hands-on session: AI in magnetism."
We will give an introductory talk (~30 minutes) about AI in magnetism and more concrete information about our recent project: "AI-accelerated detection of spin structures in Kerr-microscopy data."
Afterward, we will ask you to open your laptops and participate actively in the AI revolution. We will guide you through our repository. The goal is that participants can infer data and even train models on their own at the end of the session.
If you are interested, feel free to have a look at our paper and official repository:
Paper: Labrie-Boulay et al., Phys. Rev. Appl. 21, 014014 (2024): https://doi.org/10.1103/PhysRevApplied.21.014014
Repository (v2.0): Winkler et al., Zenodo repository: https://doi.org/10.5281/zenodo.10997175
If you would like to join, please send an email to Kilian Leutner ( kileutne@students.uni-mainz.de ) by Thursday. Kilian Leutner will eventually send around links for a smaller data repository, install instructions this week for the session.
You can participate in this session at the Physics building in Mainz in the “Medienraum” (03-431), or you can access the session via Teams using the following link: https://teams.microsoft.com/l/meetup-join/19%3ameeting_MTRhNjI4ZWYtNDkyMC00YzQ1LWIyNzgtMzkxNjAzYjNjYjY2%40thread.v2/0?context=%7b%22Tid%22%3a%2251aa2b30-c9fa-40db-b91a-3a53a8a08d85%22%2c%22Oid%22%3a%22e50b859d-212d-4ce0-b8ca-82e26bd02e43%22%7d .
(As this is a test talk, we are also happy about some feedback) | |
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30 Apr 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Joacim Rocklöv, Heidelberg University | |
In this talk I will introduce infectious diseases and their sensitivity to climate variability and change. I will describe and contrast experimental evidence with empirical observations and data. In the talk I will discuss systems and interactions enabling introduction and transmission of emergent vectors, hosts, and pathogens. I will further give examples of how mathematical process-based models and machine learning approaches are used and how they can be applied to study patterns and responses to these changes. Finally, I will talk about novel applications of machine learning in surveillance and early warnings, as well as the evaluation of interventions to guide effective responses. Slides here... | |
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Theorie-Palaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) |
| Marco Fedele, IFIC, Valencia | |
TBA | |
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02 May 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Dr. Matthias Christandl, University of Copenhagen, Denmark | |
In these days, we are witnessing amazing progress in both the variety and quality of platforms for quantum computation and quantum communication. Since algorithms and communication protocols designed for traditional 'classical' hardware do not employ the superposition principle and thus provide no gain even when used on quantum hardware, we are in need of developing specific quantum algorithms and quantum communication protocols that make clever use of the superposition principle and extract a quantum advantage. "Quantum hardware needs quantum software", so to say. Furthermore, due to noise in the qubits, known as decoherence, an additional quantum-specific software layer is required that emulates a perfect quantum machine on top of a noise one. I will demonstrate our recent work on this subject with theorems as well data from university and commercial quantum devices. | |
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07 May 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Michael Kramer, Max Planck Institute for Radio Astronomy, Bonn | |
Pulsars, the natural beacons of the universe, put physics to extreme test. As neutron stars, they are not only the densest objects in the observable universe, but they also serve as high-precision laboratories for testing the general theory of relativity. Pulsars not only allow the observation of predicted effects that cannot be observed by other methods, but they provide also extremely precise tests of the properties of gravitational waves. The latest results even use pulsars as galactic gravitational wave detectors, which detect a continuous "hum" of space-time. This buzz is, most likely, caused by the merging of supermassive black holes in the early universe. The talk gives an overview of the latest results and an outlook into the future. Slides here... | |
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Theorie-Palaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) |
| Antonela Matijašić, MPP, Munich | |
TBA | |
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08 May 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Gregor Kasieczka, Universität Hamburg | |
Latest Developments in Machine Learning | |
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14 May 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Jochem Marotzke, Max Planck Institute for Meteorology, Hamburg | |
The cause and the future of climate change | |
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15 May 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. John Bulava, Universität Bochum | |
Novel Methods in Lattice Spectroscopy | |
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16 May 2024
Seminar über Theorie der kondensierten Materie / TRR146 Seminar
F. Schmid / G. Settanni / P. Virnau / L. Stelzl 14:30 Uhr s.t., Minkowski-Raum, 05-119, Staudingerweg 7 |
| Sonya Hansen, Flatiron Institute | |
TBA | |
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Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Kenneth R. Brown, Duke University, USA | |
Conical intersections often control the reaction products of photochemical processes and occur when two electronic potential energy surfaces intersect. Theory predicts that the conical intersection will result in a geometric phase for a wavepacket on the ground potential energy surface, and although conical intersections have been observed experimentally, the geometric phase has not been directly observed in a molecular system. Here we use a trapped atomic ion system to perform a quantum simulation of a conical intersection. The ion’s internal state serves as the electronic state, and the motion of the atomic nuclei is encoded into the motion of the ions. The simulated electronic potential is constructed by applying state-dependent optical forces to the ion. We experimentally observe a clear manifestation of the geometric phase using adiabatic state preparation followed by motional state measurement. Our experiment shows the advantage of combining spin and motion degrees for quantum simulation of chemical reactions. We conclude with a discussion of future simulation directions. | |
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21 May 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Cristian Micheletti, SISSA, Trieste, Italy | |
Sampling equilibrium ensembles of dense polymer mixtures is a paradigmatically hard problem in computational physics, even in lattice-based models. For instance, using real-space Monte Carlo to sample polymer systems becomes impractical for increasing size, rigidity, and density of the chains. In response to these challenges, we introduce and apply a formalism to recast polymer sampling as a quadratic unconstrained binary optimization (QUBO) problem [1].
Thanks to this mapping, dense systems of stiff polymers on a lattice can be efficiently sampled with classical QUBO solvers, resulting in more favourable performance scaling compared to real-space Monte Carlo [2]. Tackling the same problems with the D-Wave quantum annealer leads to further performance improvements [2]. As an application, we discuss the use of the quantum-inspired encoding on a hitherto untackled problem, namely the linking probability of equilibrated melts of ring polymers, for which we unveil counterintuitive topological effects.
References
[1] C.Micheletti, P. Hauke and P. Faccioli, "Polymer physics by quantum computing", Phys. Rev. Lett. 127, 080501 (2021)
[2] F. Slongo, P. Hauke, P. Faccioli and C. Micheletti "Quantum-inspired encoding enhances stochastic sampling of soft matter systems", Sci. Adv. 9, art. no adi0204 (2023) Slides here... | |
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22 May 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Prateek Agrawal, Oxford, UK | |
Beyond the Standard Model through the Axion Lens | |
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23 May 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Dr. Hans Keßler, Universität Hamburg | |
In driven non-linear systems, various kinds of bifurcations can be observed on their route to chaos. From the evolution of Floquet multipliers one can extract information which serves as a precursor for phase transitions and dynamical instabilities. This method is applied in classical non-linear physics, for example, to obtain early warning signals.
Utilising our impressive control over an atom-cavity platform, we are able to prepare our system in various dynamical regimes and study the bifurcation experimentally in a quantum gas to obtain insights that could potentially be applied to more complex systems.
We prepare a Bose-Einstein condensate inside the centre of a cavity and pumping it perpendicular to the cavity axis with a standing wave light field. Upon crossing a critical pump strength, we observe a pitchfork phase transition from a normal to a steady state self-organized phase [1]. Employing an open three- level Dicke model, this transition can be understood as a transition between two fixpoints, indicating a pitchfork bifurcation. If the pump strength is increased further, the system undergoes a Hopf bifurcation. This causes limit cycles, which have time crystalline properties, to emerge [2]. In this regime, our model no longer shows fixpoints but stable attractive periodic orbits [3]. For strong pumping, we observe a second bifurcation, in our case a Neimark-Sacker bifurcation. Its main characteristics is an oscillation with two incommensurate frequencies, this may indicate the formation of a continuous time quasicrystal [4]. Finally, in the regime of very strong pumping, we observe chaotic dynamics with many contributing frequencies.
References:
[1] J. Klinder, et al., PNAS 112, 11 (2015)
[2] P. Kongkhambut, et al., Science 307 (2022)
[3] J. Skulte, et al., arXiv:2401.05332 (2023)
[4] P. Kongkhambut, et al., manuscript in preparation | |
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28 May 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Ingo Rehberg, University of Bayreuth | |
Spherical magnets are an invaluable but affordable physics toy! While vividly demonstrating chemical, physical and mathematical problems, they can also greatly inspire creativity: Questions concerning the favoured state of dipole cluster configurations lead – via an encounter with tipping points – to the invention of magnetic gears based on degenerate continua. Open source animations and patent-free hardware to play with shall garnish this triptychon. Slides here... | |
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29 May 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Kathrin Valerius, KIT | |
Weighing the Neutrino with KATRIN - Latest Results and Future Prospects | |
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04 Jun 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Claudia Felser, Max Planck Institute for Chemical Physics of Solids, Dresden | |
Topology, a well-established concept in mathematics, has nowadays become essential to describe condensed matter. At its core are chiral electron states on the bulk, surfaces and edges of the condensed matter systems, in which spin and momentum of the electrons are locked parallel or anti-parallel to each other. Magnetic and non-magnetic Weyl semimetals, for example, exhibit chiral bulk states that have enabled the realization of predictions from high energy and astrophysics involving the chiral quantum number, such as the chiral anomaly, the mixed axial-gravitational anomaly and axions. The potential for connecting chirality as a quantum number to other chiral phenomena across different areas of science, including the asymmetry of matter and antimatter and the homochirality of life, brings topological materials to the fore. Slides here... | |
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05 Jun 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Jacobo López-Pavón, Universidad de Valencia, Spain | |
Recent Developments in Heavy Neutral Leptons | |
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06 Jun 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Nicolò Defenu, ETH Zürich | |
The concept of universality has shaped our understanding of many-body physics, but is mostly limited to homogenous systems. The seminar introduces a definition of universal scaling on a non-homogeneous graph. The corresponding scaling theory is expected to depend only on a single parameter, the spectral dimension ds, which plays the role of the relevant parameter on complex geometries. We will then focus on a concrete example, the long-range diluted graph (LRDG), which allows to tune the value of the spectral dimension continuously. By means of extensive numerical simulations, we probe the scaling exponents of a simple instance of O(N) symmetric models on the LRDG showing quantitative agreement with the theoretical prediction of universal scaling in fractional dimensions. | |
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11 Jun 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Dr. Karen Alim, TU München | |
Propagating, storing and processing information is key to take smart decisions – for organisms as well as for autonomous devices. In search for the minimal units that allow for complex behaviour, the slime mould Physarum polycephalum stands out by solving complex optimization problems despite its simple make-up. Physarum’s body is an interlaced network of fluid-filled tubes lacking any nervous system, in fact being a single gigantic cell. Yet, Physarum finds the shortest path through a maze. We unravel that Physarum’s complex behaviour emerges from the physics of active flows shuffling through its tubular networks. Flows transport information, information that is stored in the architecture of the network. Thus, tubular adaptation drives processing of information into complex behaviour. Taking inspiration from the mechanisms in Physarum we outline how to embed complex behaviour in active microfluidic devices and how to program human vasculature. Slides here... | |
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12 Jun 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Jessica Turner, Durham University, UK | |
Primordial Black Holes and Leptogenesis | |
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13 Jun 2024
Seminar über Theorie der kondensierten Materie / TRR146 Seminar
F. Schmid / G. Settanni / P. Virnau / L. Stelzl 14:30 Uhr s.t., Minkowski-Raum, 05-119, Staudingerweg 7 |
| Dr. Narendra Kumar, BionTech | |
Industry Talk on BionTech | |
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Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14 Uhr c.t., IPH Lorentzraum 05-127 |
| Prof. Eugene Polzik, University of Copenhagen, Denmark | |
Studies of extreme cases within quantum mechanics have always been particularly attractive. How macroscopic can objects be and still demonstrate unique quantum features, such as entanglement? What are the real limits of measurement precision in quantum mechanics? I will review our experiments where macroscopic objects are driven deep into the quantum regime. Observation of a quantum trajectory of motion in a quantum reference frame with, in principle, unlimited accuracy will be presented. A concept of a reference frame with an effective negative mass required for such observation will be introduced. Generation of an entangled Einstein-Podolsky-Rosen state between distant mechanical and atomic oscillators and progress towards application of those ideas to gravitational wave detection will be reported. Finally, a recent demonstration of entanglement enhanced magnetic induction tomography for medical applications will be presented. | |
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18 Jun 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Dr. Thomas Cocolios, KU Leuven, Belgium | |
Nuclear medicine is currently experiencing some major changes and developments: Lu-177 has become a standard radionuclide for patient care, in particular with Lutathera® and Pluvito®, two recently marketed drug for endocrine and prostate cancers, respectively. Those successes are but the tip of the iceberg of possibilities: with 3000 radionuclides synthesized in the laboratory, it seems unbelievable that only a handful are actually used in medical applications. This is mostly due to the absence of a supply pipeline to support research until their production is picked up by the industry. To break that paradigm, CERN has established the MEDICIS facility (MEDical Isotopes Collected from ISolde), where the techniques developed for the last 50 years on radioactive ion beams are now applied to produce medical radionuclides for research. The success of the development of non-carrier-added Sm-153 has led it to first clinical trials in 2024. At the European level, this has triggered a new consortium, federated around MEDICIS but with a larger reach, as PRISMAP, the European medical radionuclide programme. Slides here... | |
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19 Jun 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Dr. Joel Swallow, CERN, Switzerland | |
New Results From the NA62 Experiment | |
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20 Jun 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14 Uhr c.t., IPH Lorentzraum 05-127 |
| Dr. Janis Nötzel, TUM, München | |
In this talk, we address the question of how some theoretically predicted quantum advantages could be utilized in future system design. We start with an overview of various theoretical descriptions of quantum communication systems, focusing mainly on data transmission tasks involving topics such as Holevo capacity and entanglement-assisted capacity of a quantum channel as well as the use of entanglement for coordination in multiple access scenarios. We give a brief overview of the state of the art of implementations before moving on to an applied perspective, where we start from the state of the art in today's network design and explore the potential role of the above-mentioned quantum system descriptions for future networks.
We conclude the talk by formulating system design questions. | |
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25 Jun 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Klaus Blaum, Max-Planck Institute for Nuclear Physics | |
The four fundamental interactions and their symmetries, the fundamental constants as well as the properties of elementary particles like masses and moments, determine the basic structure of the universe and are the basis for our so well tested Standard Model (SM) of physics. Performing stringent tests on these interactions and symmetries in extreme conditions at lowest energies and with highest precision by comparing, e.g., the properties of particles and their counterpart, the antiparticles, will allow us to search for physics beyond the SM. Any improvement of these tests beyond their present limits requires novel experimental techniques.
An overview is given on recent mass and g-factor measurements with extreme precision on single or few cooled ions stored in Penning traps. Among others the most stringent test of bound-state quantum electrodynamics could be performed. Here, the development of a novel technique, based upon the coupling of two ions as an ion crystal, enabled the most precise determination of a g-factor difference to date. This difference, determined for the isotopes 20,22Ne9+ with a relative precision of 5 × 10−13, improved the precision for isotopic shifts of g factors by about two orders of magnitude. Our latest results on precision measurements with exotic ions in Penning traps will be presented. Slides here... | |
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26 Jun 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Dr. Alessandro Lovato, Argonne National Lab, USA | |
Uncertainty Quantification in Nuclear Physics | |
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27 Jun 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Oded Zilberberg, Universität Konstanz | |
Topological classification of matter has become crucial for understanding (meta-)materials, with associated quantized bulk responses and robust topological boundary effects [1]. Topological phenomena have also recently garnered significant interest in nonlinear systems [2]. In particular, weak nonlinearities can result in parametric gain, leading to “non-Hermitian” metamaterials and the associated topological classification of open systems [3]. Here, we venture into this expanding frontier using an approach that moves away from quasilinear approximations around the closed system classification. We harness instead the topology of structural stability of vector flows, and thus propose a new topological graph invariant to characterize nonlinear out-of-equilibrium dynamical systems via their equations of motion. We exemplify our approach on the ubiquitous model of a dissipative bosonic Kerr cavity, subject both to one- and two-photon drives. Using our classification, we can identify the topological origin of phase transitions in the system, as well as explain the robustness of a multicritical point in the phase diagram. We, furthermore, identify that the invariant distinguishes population inversion transitions in the system in similitude to a Z2 index. Our approach is readily extendable to coupled nonlinear cavities by considering a tensorial graph index.
References
[1] T. Ozawa, H. M. Price, A. Amo, N. Goldman, M. Hafezi, L. Lu, M. Rechtsman, D. Schuster, J. Simon, O. Zilberberg, and I. Carusotto, Rev. Mod. Phys. 91, 015006 (2019).
[2] A. Szameit, and M. C. Rechtsman, Nat. Phys. (2024).
[3] K. Ding, C. Fang, and G. Ma, Nat. Rev. Phys. 4, 745 (2022). | |
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02 Jul 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Laura Kreidberg, Max Planck Institute for Astronomy, Heidelberg | |
The recent launch of the James Webb Space Telescope (JWST) has revolutionized the field of exoplanet atmosphere characterization, thanks to its unprecedented sensitivity and broad wavelength coverage. In this talk, I will give a tour of the latest JWST results for transiting exoplanets, from gas giants down to rocky worlds. For the largest planets, I'll focus on the complex physical processes recently revealed in their atmospheres, including photochemistry, 3D effects, and cloud formation. Pushing down to smaller worlds, I'll share the first measurements of chemical composition for the elusive sub-Neptune population; and finally give an update on which (if any) rocky planets have atmospheres at all. Slides here... | |
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Theorie-Palaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) |
| Jorinde van de Vis, Leiden U. | |
TBA | |
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03 Jul 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| PD Dr. Teresa Marrodan, MPI Heidelberg | |
Update on XENON Analyses and Outlook on DARWIN/XLZD | |
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09 Jul 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Dr. Kerem Çamsarı, University of California, Santa Barbara | |
tba | |
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10 Jul 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Louis Strigari, Texas University, USA | |
Astrophysical and Terrestrial Applications of Coherent Neutrino Scattering | |
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11 Jul 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Nir Bar-Gill, Hebrew University, Jerusalem | |
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 bath characterization, 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). This approach suppresses sensitivity to coherent errors while enabling noise characterization, providing a useful tool for the study of complicated open quantum systems, with the potential for contributions to enhanced sensing. I will then present a general theoretical framework we developed for Hamiltonian engineering in an interacting spin system [2]. This framework is applied to the coupling of the spin ensemble to a spin bath, including both coherent and dissipative dynamics [3]. 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 advanced techniques for improving sensing bandwidth using compressed sensing and machine learning. Demonstrations of NV sensing capabilities will include measurements of 2D vdW magnetic materials, and specifically the phase transition of FGT through local imaging of magnetic domains in flakes of varying thicknesses [4], as well as a technique for sensing radical concentrations through the change in the charge state of shallow NVs ([5], in collaboration
with Uri Banin).
1. P. PENSHIN ET. AL., SUBMITTED.
2. K. I. O. BEN’ATTAR, D. FARFURNIK AND N. BAR-GILL, PHYS. REV. RESEARCH 2, 013061 (2020).
3. K. I. O. BEN’ATTAR ET. AL., IN PREPARATION.
4. G. HAIM ET. AL., IN PREPARATION.
5. Y. NINIO ET. AL., ACS PHOTONICS 8, 7, 1917-1921 (2021). | |
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16 Jul 2024
Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Dr. Frank Saueressig, Radboud University, NL | |
Fusing the principles of general relativity and quantum mechanics in a consistent theoretical framework still constitutes one of the main open challenges in theoretical physics today. Over the last decades, the gravitational asymptotic safety program has taken significant steps towards achieving this goal. A central virtue, driving the success of the approach, is its conservative nature: the program builds on well-established principles of quantum field theory and extends them in a rather minimalistic way. In this talk, we will review the key developments in the program, building up to its present status. I will also attempt to give an outlook on the challenges that need to still be addressed in the future. Slides here... | |
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Physikalisches Kolloquium
Institut für Physik 16:15 Uhr s.t., HS KPH |
| Prof. Dr. Reinhard Noack, Philipps University Marburg | |
Colloquium in honor of Prof. Dr. Peter G. J. van Dongen and Prof. Dr. Martin Reuter (Part 2): Correlated Electrons from Zero to Infinite Dimensions: Early Days of KOMET in Mainz | |
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17 Jul 2024
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7 |
| Prof. Dr. Stefan Schoenert, TU Munich | |
LEGEND and the Quest for Majorana Neutrinos | |
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18 Jul 2024
Seminar über Quanten-, Atom- und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05-127 |
| Prof. Dominik Bucher, TUM, München | |
The nitrogen-vacancy (NV) point defect in diamond has emerged as a new class of quantum sensor, enabling the detection of magnetic fields on unprecedented length scales. This technique allows the measurement of magnetic resonance signals on the nanoscale down to a single electronic or nuclear spin. In my talk, I will briefly introduce the fundamentals of diamond-based quantum sensing. In the second part, I will discuss recent developments in my group to use the optical readout of the NV centres to perform magnetic resonance microscopy in real space inside microfluidic structures. The remaining obstacles to this novel microscopy technique and future goals are discussed in the final part. | |
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