Recently discovered kagome superconductors AV3Sb5 (A = K, Rb, Cs) exhibit exotic bulk and surface physical properties such as charge-density wave (CDW) and chirality, whereas their origins remain unresolved. By using micro-focused angle-resolved photoemission spectroscopy, we discovered that AV3Sb5 commonly exhibits two distinct polar surfaces depending on the termination; electron- and hole-doped ones for the A- and Sb-termination, respectively. We observed that the kagome-derived band shows a clear splitting in the A-terminated surface while it is absent in the Sb-terminated counterpart, indicative of the polarity-dependent CDW at the surface. Close comparison of the band-dependent splitting reveals that the three-dimensional CDW structure of the K-terminated surface is different from that of the Rb- or Cs-terminated surface, suggesting the diversity of the CDW ground state. These results provide important insight into the origin of CDW in kagome superconductors AV3Sb5.
@article{arxiv.2301.12034,
title = {Surface-termination-dependent electronic states in kagome superconductors AV3Sb5 (A = K, Rb, Cs) studied by micro-ARPES},
author = {Takemi Kato and Yongkai Li and Min Liu and Kosuke Nakayama and Zhiwei Wang and Seigo Souma and Miho Kitamura and Koji Horiba and Hiroshi Kumigashira and Takashi Takahashi and Yugui Yao and Takafumi Sato},
journal= {arXiv preprint arXiv:2301.12034},
year = {2023}
}