Cs V3Sb5: A Z2 Topological Kagome Metal with a Superconducting Ground State

Abstract

Recently discovered alongside its sister compounds KV3Sb5 and RbV3Sb5, CsV3Sb5 crystallizes with an ideal kagome network of vanadium and antimonene layers separated by alkali metal ions. This work presents the electronic properties of CsV3Sb5, demonstrating bulk superconductivity in single crystals with a Tc=2.5 K. The normal state electronic structure is studied via angle-resolved photoemission spectroscopy and density-functional theory, which categorize CsV3Sb5 as a Z2 topological metal. Multiple protected Dirac crossings are predicted in close proximity to the Fermi level (EF), and signatures of normal state correlation effects are also suggested by a high-temperature charge density wavelike instability. The implications for the formation of unconventional superconductivity in this material are discussed.