Universal phase diagram of superconductivity and charge density wave versus high hydrostatic pressure in pure and Se-doped 1T−TaS2

Abstract

Various phase diagrams of charge density wave (CDW) and superconductivity (SC) have been reported in layered transition-metal dichalcogenides. Some of the ordered phases in these diagrams are not universal because they rely on different critical factors, leading to the proliferation of contradictory arguments about CDWs and SC. Here, the authors use cubic anvil high-pressure apparatus to explore the intrinsic pressure phase diagrams of 1$T$-Ta(S, Se)${}_{2}$. A universal superconducting phase diagram is revealed on the border of the CDW domain of existence. Pressure-induced bulk SC emerges along with the complete collapse of various CDWs. The superconducting transition temperature increases up to 15 GPa without the usually reported dome.