Competition between Antiferromagnetism and Superconductivity in the Electron-Doped Cuprates Triggered by Oxygen Reduction

Abstract

We have performed a systematic angle-resolved photoemission study of as-grown and oxygen-reduced ${\mathrm{Pr}}_{2\ensuremath{-}x}{\mathrm{Ce}}_{x}{\mathrm{CuO}}_{4}$ and ${\mathrm{Pr}}_{1\ensuremath{-}x}\mathrm{La}{\mathrm{Ce}}_{x}{\mathrm{CuO}}_{4}$ electron-doped cuprates. In contrast with the common belief, neither the band filling nor the band parameters are significantly affected by the oxygen reduction process. Instead, we show that the main electronic role of the reduction process is to remove an anisotropic leading edge gap around the Fermi surface. While the nodal leading edge gap is induced by long-range antiferomagnetic order, the origin of the antinodal one remains unclear.