Surface-termination-dependent electronic states in kagome superconductors AV3Sb5 (A = K, Rb, Cs) studied by micro-ARPES

Takemi Kato; Yongkai Li; Min Liu; Kosuke Nakayama; Zhiwei Wang; Seigo Souma; Miho Kitamura; Koji Horiba; Hiroshi Kumigashira; Takashi Takahashi; Yugui Yao; Takafumi Sato

doi:10.1103/physrevb.107.245143

arXiv · 2301.12034

Surface-termination-dependent electronic states in kagome superconductors AV3Sb5 (A = K, Rb, Cs) studied by micro-ARPES

Takemi Kato·Yongkai Li·Min Liu·Kosuke Nakayama·Zhiwei Wang·Seigo Souma·Miho Kitamura·Koji Horiba·Hiroshi Kumigashira·Takashi Takahashi·Yugui Yao·Takafumi Sato

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Abstract

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.

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Takemi Kato, Yongkai Li, Min Liu, Kosuke Nakayama, Zhiwei Wang, Seigo Souma, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Takashi Takahashi, Yugui Yao, Takafumi Sato. 2023-01-28. Surface-termination-dependent electronic states in kagome superconductors AV3Sb5 (A = K, Rb, Cs) studied by micro-ARPES. https://doi.org/10.1103/physrevb.107.245143

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