High-resolution ARPES study of electron-doped Fe-based superconductor BaFe1.85Co0.15As2

Abstract

We have performed high-resolution angle-resolved photoemission spectroscopy of an electron-doped iron-based superconductor BaFe1.85Co0.15As2, and experimentally determined the Fermi-surface, the band structure and the superconducting gap. We found an isotropic s-wave-like superconducting gap on a hole pocket centered at the Γ point and on electron pockets at the M point. The superconducting gap magnitude is significantly enhanced on the Fermi-surfaces connected by the antiferromagnetic wave vector, suggesting the importance of an interband interaction on the pairing mechanism.