CsV3Sb5 : A Z2

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 angleresolved photoemission spectroscopy (ARPES) and density functional theory (DFT), 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 wave-like instability. The implications for the formation of unconventional superconductivity in this material are discussed.

Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal

“…As shown in Fig. 1a , an anomaly due to the CDW transition in the resistivity 15 is clearly visible for sample 1 with PCC. The CDW transition temperature T * gradually decreases with increasing the pressure, and the anomaly becomes much weaker at high pressures.…”

“…Figure 2 a, b shows superconducting transition under different magnetic fields for sample 1 with PCC around P1 and P2 with magnetic field applied along c axis, respectively. Much higher magnetic field is needed to suppress superconductivity around P1 and P2 compared with that at ambient pressure 15 , 18 . To investigate the evolution of H c2 under pressure, we plot H c2 (determined by ) as a function of temperature under various pressures, as shown in Fig.…”

“…These materials crystallize in the P 6/mmm space group, forming layers of ideal kagome nets of V ions coordinated by Sb. Besides topological properties, A V 3 Sb 5 exhibits both CDW 13 , 14 and superconductivity 15 – 17 . Ultra-low temperature thermal conductivity measurements on CsV 3 Sb 5 single crystal shows a finite residual linear term, implying an unconventional nodal superconductivity 18 .…”

Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal

“…Material syntheses. Single crystals of CsV 3 Sb 5 were synthesized via a self-flux growth method similar to the previous reports 15 . In order to prevent the reaction of Cs with air and water, all the preparation processes were performed in an argon glovebox.…”

“…With further increasing the pressure, the T c is monotonically suppressed and completely disappears above 12 GPa as shown in PCC around P1 and P2 with magnetic field applied along c axis, respectively. Much higher magnetic field is needed to suppress superconductivity around P1 and P2 compared with that at ambient pressure 15,18 . To investigate the evolution of H c2 under pressure, we plot H c2 (determined by ) as a function of T c under various pressures as shown in Fig.…”