EFFECT OF OXYGEN DOPING AND HIGH PRESSURE ON THE ELECTRONIC STRUCTURE OF HgBa2CuO4+δ AND SUPERCONDUCTIVITY

Abstract

The effects of oxygen doping (δ=0~0.19) and high pressure (P=0~5.07 GPa) on the electronic structure of HgBa2CuO4+δ have been studied by the recursion method. The hole concentration of the CuO2 layer increases monotonically as δ increases from 0 to 0.19. Each excess oxygen atom contributes about 1.9 holes to the CuO2 layer. The pressure-induced charge transfer, dn/dP, decreases for increasing δ, vanishing at over-doping level, which is consistent with the δ-dependence of dT c /dP observed in experiments.