Multiple energy scales and anisotropic energy gap in the charge-density-wave phase of the kagome superconductor CsV3Sb5

Kosuke Nakayama, Yongkai Li, Takemi Kato, Min Liu, Zhiwei Wang, Takashi Takahashi, Yugui Yao, Takafumi Sato

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Kagome metals AV3Sb5 (A=K, Rb, and Cs) exhibit superconductivity at 0.9-2.5 K and charge-density wave (CDW) at 78-103 K. Key electronic states associated with the CDW and superconductivity remain elusive. Here, we investigate low-energy excitations of CsV3Sb5 by angle-resolved photoemission spectroscopy. We found an energy gap of 50-70 meV at the Dirac-crossing points of linearly dispersive bands, pointing to an importance of spin-orbit coupling. We also found a signature of strongly Fermi-surface and momentum-dependent CDW gap characterized by the larger energy gap of maximally 70 meV for a band forming a saddle point around the M point, the smaller (0-18 meV) gap for a band forming massive Dirac cones and a zero gap at the Γ/A-centered electron pocket. The observed highly anisotropic CDW gap which is enhanced around the M point signifies an importance of scattering channel connecting the saddle points, laying foundation for understanding the nature of CDW and superconductivity in AV3Sb5.

Original languageEnglish
Article numberA83
JournalPhysical Review B
Volume104
Issue number16
DOIs
Publication statusPublished - 2021 Oct 15

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Multiple energy scales and anisotropic energy gap in the charge-density-wave phase of the kagome superconductor CsV3Sb5'. Together they form a unique fingerprint.

Cite this