Observation of d x 2 -y 2 -Like Superconducting Gap in an Electron-Doped High-Temperature Superconductor

Abstract
High-resolution angle-resolved photoemission spectroscopy of the electron-doped high-temperature superconductor Nd2-xCexCuO4 (x = 0.15, transition temperature T c = 22 K) has found the quasiparticle signature as well as the anisotropicd x2-y2 –like superconducting gap. The spectral line shape at the superconducting state shows a strong anisotropic nature of the many-body interaction. The result suggests that the electron-hole symmetry is present in the high-temperature superconductors.