Electronic Structure of Novel Superconductor doped-ZrPSe

In this paper we report the results of the first-principles calculations for cation and anion co-doped system (Zr1-yYy)P(As0.25Se0.75) using virtual crystal approximation. The density of states at the Fermi level (=D(EF)) shows a dome-shape with respect to the doping concentration y. This result qualitatively explains the observed y dependence of Tc, especially for (Zr1-yYy)P1.25Se0.75. We also found the similarity of the band structure between ZrSiS and doped-ZrPSe. Characteristic band crossing near E-g, which is found to be the Dirac line node in ZrSiS, is also found in doped-ZrPSe. This result strongly suggests that the superconductivity and the Dirac line node are co-existed in doped-ZrPSe.