Coexistence of superconductivity and commensurate charge density wave in 4Hb-TaS2−xSex single crystals

Abstract

The transition-metal dichalcogenides, a family of graphene-like two-dimensional (2D) materials, exhibit exciting properties for potential applications and fundamental researches. We successfully fabricated a new series of 4Hb-TaS2−xSex (0 ≤ x ≤ 1.5) single crystals by chemical vapor transport technique. This is the first time to demonstrate the coexistence of superconductivity and commensurate charge density wave (CCDW) in 4Hb-TaS2−xSex (0 ≤ x ≤ 1.5). The evolution of the electronic states tuned by Se-doping are also exhibited in the phase diagram. Taking into account the special crystal structure of 4Hb-TaS2−xSex (0 ≤ x ≤ 1.5), we draw a conclusion that the H- and T-layers play a crucial role to dominate the state of superconductivity and CCDW, respectively.