Superconductivity induced by Se-doping in layered charge-density-wave system 1<i>T</i>-TaS2−<i>x</i>Se<i>x</i>

Abstract

Layered 1T-TaS2–xSex (0≤x≤2) single crystals have been systematically fabricated by a chemical vapor transport technique. Surprisingly, the superconductivity is induced by the Se doping. We demonstrate the appearance of a series of electronic states: the Mott phase melts into a nearly commensurate charge-density-wave (CDW) phase, superconductivity in a wide x range develops within the nearly commensurate CDW state, and finally commensurate CDW phase reproduces for heavy Se content. The rich phase diagram provides an ideal platform to investigate the interplay between electron correlation, CDW, and superconductivity, as well as the potential applications in electronic devices.