Weak coupling Bardeen-Cooper-Schrieffer suerconductivity in the Electron-Doped Cuprate Superconductors

Abstract

We use in-plane tunneling spectroscopy to study the temperature dependence of the local superconducting gap $Δ(T)$ in electron-doped copper oxides with various $T_c$'s and Ce-doping concentrations. We show that the temperature dependence of $Δ(T)$ follows the expectation of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity, where $Δ(0)/k_{B}T_{c}\approx1.72\pm 0.15$ and $Δ(0)$ is the average superconducting gap across the Fermi surface, for all the doping levels investigated. These results suggest that the electron-doped superconducting copper oxides are weak coupling BCS superconductors.

5 pages, 4 figures