Weak coupling BCS suerconductivity in the Electron-Doped Cuprate Superconductors

We use in-plane tunneling spectroscopy to study the temperature dependence of the local su- perconducting gap �(T) in electron-doped copper oxides with various Tc's and Ce-doping con- centrations. We show that the temperature dependence of �(T) follows the expectation of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity, where �(0)/kBTc � 1.72 ± 0.15 and �(0) is the average superconducting gap across the Fermi surface, for all the doping levels inves- tigated. These results suggest that the electron-doped superconducting copper oxides are weak coupling BCS superconductors.