Charge-density-wave melted superconductivity in 1T-TiSe₂

Abstract

Understanding the origin of superconductivity and the interplay between superconductivity and charge-density wave (CDW) in transition-metal dichalcogenides (TMDs) is one of fundamental interests in scientific research as well as in applications. In this work, we have explored the inherent physical mechanism for the superconducting transition in Ta-doped 1T-TiTaxSe2 single crystals by combining density functional theory (DFT) calculations and experiment approaches. The theoretical calculation results reveal that with Ta doping, the CDW is suppressed by the raising of chemical potential, which is further confirmed by x-ray absorption near-edge structure (XANES) and low-temperature Raman spectra. And then, the superconductivity is motivated by the enhancement of density of states near the Fermi level. Our present results shed new light on understanding the emergence of superconductivity within the CDW phase, as well as the potential applications in electronic devices.