Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 27: 2D Materials: Electronic structure, excitations, etc. II (joint session O/HL/TT)

HL 27.2: Talk

Wednesday, March 11, 2026, 10:45–11:00, TRE/MATH

Chirality in the Kagome Metal CsV₃Sb₅ — •Tom P. Lammerskötter¹, H.J. Elmers², G. Schönhense², O. Tkach², Y. Lytvynenko², H. Agarwal², S. Chernov³, M. Hoesch³, D. Kutnyakhov³, M. Scholz³, K. Rossnagel⁴, A. Gloskovskii³, C. Schlueter³, A. Winkelmann⁵, A. Haghighirad⁶, M. Schmitt⁷, T. Lee⁷, R. Claessen⁸, M. Le Tacon⁶, J Demsar², and O. Fedchenko¹ — ¹Goethe-Universität Frankfurt (Germany) — ²JGU Mainz (Germany) — ³DESY Hamburg (Germany) — ⁴Universität zu Kiel (Germany) — ⁵AGH University of Krakow (Poland) — ⁶KIT Karlsruhe (Germany) — ⁷DIAMOND (UK) — ⁸Universität Würzburg (Germany)

Kagome metals AV₃Sb₅ (A = Cs, K, Rb) exhibit flat bands, Dirac points, and van Hove singularities that drive unconventional charge-density-wave (CDW) order and topological states. We study chirality in CsV₃Sb₅ using angle-resolved photoemission spectroscopy (ARPES) and x-ray photoelectron diffraction (XPD) with circularly polarized photons. XPD reveals a local crystal chirality in the CDW phase. ARPES shows pronounced magnetic circular dichroism (MCD), demonstrating a chiral electronic structure and indicating orbital moments possibly linked to loop-current order. To probe orbital-moment coupling, we study Nb-doped CsV₃Sb₅, where band broadening and enhanced Dirac-like gaps occur. In the CDW phase, the strongly increased MCD indicates time-reversal-symmetry breaking and couples to the three van Hove singularities at the M points.

Keywords: Chirality; Kagome; CDW; van Hove singularities; ARPES