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arXiv · 2412.02599

Evidence for reduced periodic lattice distortion within the Sb-terminated surface layer of the kagome metal CsV$_3$Sb$_5$

Felix Kurtz·Gevin von Witte·Lukas Jehn·Alp Akbiyik·Igor Vinograd·Matthieu Le Tacon·Amir A. Haghighirad·Dong Chen·Chandra Shekhar·Claudia Felser·Claus Ropers
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Abstract

The discovery of the kagome metal CsV$_3$Sb$_5$ sparked broad interest, due to the coexistence of a charge density wave (CDW) phase and possible unconventional superconductivity in the material. In this study, we use low-energy electron diffraction (LEED) with a $\mu$m-sized electron beam to explore the periodic lattice distortion at the antimony-terminated surface in the CDW phase. We recorded high-quality backscattering diffraction patterns in ultrahigh vacuum from multiple cleaved samples. Unexpectedly, we did not find superstructure reflexes at intensity levels predicted from dynamical LEED calculations for the reported $2 \times 2 \times 2$ bulk structure. Our results suggest that in CsV$_3$Sb$_5$ the periodic lattice distortion accompanying the CDW is less pronounced at Sb-terminated surfaces than in the bulk.

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Felix Kurtz, Gevin von Witte, Lukas Jehn, Alp Akbiyik, Igor Vinograd, Matthieu Le Tacon, Amir A. Haghighirad, Dong Chen, Chandra Shekhar, Claudia Felser, Claus Ropers. 2024-12-03. Evidence for reduced periodic lattice distortion within the Sb-terminated surface layer of the kagome metal CsV$_3$Sb$_5$. https://doi.org/10.1103/physrevb.111.l140101

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