Effect of sulfur doping on superconductivity and charge density wave order in Kagome metal CsV3(Sb1-xSx)5

Recently, the coexistence and competition of superconductivity (SC) and charge density wave (CDW) have emerged in Kagome superconductor AV(3)Sb(5) (A = K, Rb, Cs) under pressure, which has aroused widespread interest. Here, chemical substitution is used to introduce chemical pressure to further investigate the coexistence and competition between CDW and SC states. By preparing CsV3(Sb1-xSx)(5) series single crystals and studying their crystal structure, chemical valence states, SC, and electronic transport behavior, it is found that S doping causes significant chemical pressure that is similar to axial mechanical pressure, resulting in suppression on the CDW and enhancement on SC. The T-c-x relationship exhibits a double dome SC, similar to the behavior observed in the CsV3Sb5 under mechanical pressure. In addition, a negative correlation between T-CDW and the disorder degree (measured by residual resistivity) is observed. This correlation is consistent with the observed translational jump in the rho(T) curve before and after the CDW transition, that is, the temperature coefficient of resistivity does not change before and after the CDW phase transition, but only the resistivity curve shifts to a certain value. This phenomenon reveals that disorder is an important factor affecting the CDW transition of the system. Further, S doping also induces hole band filling effect that results in a decrease in the DOS at E-F and consequently counterbalances the T-c enhancement effect from chemical pressure to a certain extent. The electronic phase diagram of the CsV3(Sb1-xSx)(5) system is accordingly established, which demonstrates the correlation between the SC, CDW, disorder degree, and other electronic nature of the system.