DPG (Deutsche Physikalische Gesellschaft e. V.)

Mittwoch, 29. März 2023, 11:30–11:45, HSZ 204

Effect of cation dynamics on polar instabilities of perovskite derived structures — •Rinis Ferizaj1, Florian Büscher1, Peter Lemmens1, Hiroshi Kageyama2, and Tong Zhu2 — 1IPKM, TU Braunschweig — 2Energy Chemistry, Univ. Kyoto, Japan

Perovskite derived structures have a huge variability in structural, electronic and magnetic properties. This makes them leading candidates for todays search for novel energy materials. Using Raman scattering we probe phonon dynamics in such material and focus to the cation dynamics to better understand transitions into different polar/nonpolar low temperature phases.

We acknowledge support by DFG GrK 1952/2, Metrology for Complex Nanosystems-NanoMet, and DFG EXC-2123 QuantumFrontiers - 390837967.

Freitag, 31. März 2023, 11:15–11:30, HSZ 201

Inelastic topological light scattering in chiral liquids — Silvia Müllner1, Florian Büscher1, Angela Möller2, and •Peter Lemmens1 — 1IPKM, TU Braunschweig — 2Anorg. Chemie, JGU Mainz

Vortex beams of light contain spin (SAM, helicity) and angular momentum (OAM, chirality). However, there is a long debate whether OAM can couple to a topological system. In a recent experimental study of chiral liquid crystals we demonstrate the effect of vortex light with different topological charge. We give evidence for roton like quasiparticles with a dispersion that dominates the scattering at small and intermediate scattering vectors [1].

Work supported by DFG LE967/16-1, GrK 1952/2, Metrology for Complex Nanosystems*NanoMet, and DFG EXC-2123 QuantumFrontiers - 390837967.
[1] S. Müllner, F. Büscher, A. Möller, and P. Lemmens, Phys. Rev. Lett. 129, 207801 (2022)