Wochenübersicht für die Woche vom

08 Jul 2024 bis 14 Jul 2024 (KW 28)

KW27 - KW28 - KW29 - KW30

08 Jul 2024

RHIND seminar on Mathematical Physics and String Theory

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

16:00 Uhr s.t., None

Catherine Meusburger, University of Erlangen
Dijkgraaf-Witten TQFT with defects
at Zoom, BigBlueButton

09 Jul 2024

Physikalisches Kolloquium

Institut für Physik

16:15 Uhr s.t., HS KPH

- canceled - Dr. Kerem Çamsarı, University of California, Santa Barbara


Institut für Physik

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

Peter Reimitz, Sao Paulo U.
High-luminosity colliders and fixed-target facilities using proton beams are sensitive to new weakly coupled degrees of freedom across a broad mass range. In this talk, we will discuss various production modes for dark vector particles in proton beam experiments. First, we will set the stage by reviewing light physics models, including new vector particles, discuss how these models could solve the shortcomings of the SM, and present some current and future search strategies. After briefly discussing dark photon production in meson decays and Drell-Yan, we will have a closer look at dark bremsstrahlung. Dark bremsstrahlung is particularly important for dark vectors with masses between 0.5-1.5 GeV due to resonant mixing with hadronic resonances. This production mode will be crucial for sensitivity predictions for future experiments like SHiP and proposals like the Forward Physics Facility. We revisit the calculation of dark photons via initial state radiation in non-single diffractive scattering, using an improved approach to the splitting function and the timelike electromagnetic form factor.


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

zukünftige Termine
11 Jul 2024

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

Institut für Physik

14 Uhr c.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).

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

Lisa Hartung, Prof

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


14:00 Uhr s.t., 01 122 Newton-Raum

Satoru Emori, Department of Physics, Virginia Polytechnic Institute and State University, U.S.A.
Energy-efficient spintronic devices require a large spin-orbit torque (SOT) and low damping to excite magnetic precession. In conventional devices based on heavy-metal/ferromagnet bilayers, reducing the ferromagnet thickness to ~1 nm enhances the torque – but dramatically increases the damping. I will present my team’s new approach toward attaining low damping and a sizable SOT in single-layer, 10-nm-thick FeNi alloys. A vertical Fe:Ni compositional gradient is designed to provide the necessary asymmetry for SOT generation. We confirm low effective damping in FeNi even with a steep compositional gradient. More remarkably, we reveal a sizable anti-damping SOT even without any intentional compositional gradient. Through noninvasive depth-profile measurements, we identify a lattice strain gradient as the key asymmetry giving rise to the SOT. Our findings provide fresh insights into damping and SOTs in single-layer ferromagnets for power-efficient spintronic devices.