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

TL;DR

This study demonstrates that electron-doped cuprate superconductors exhibit BCS-like weak coupling behavior, with the superconducting gap following the temperature dependence predicted by BCS theory across various doping levels.

Contribution

The paper provides experimental evidence that electron-doped copper oxides behave as weak coupling BCS superconductors, with consistent gap ratios across different doping concentrations.

Findings

Superconducting gap follows BCS temperature dependence

Gap ratio Δ(0)/kBTc ≈ 1.72 across doping levels

Electron-doped cuprates are weak coupling BCS superconductors

Abstract

We use in-plane tunneling spectroscopy to study the temperature dependence of the local superconducting gap $\Delta(T)$ in electron-doped copper oxides with various $T_c$'s and Ce-doping concentrations. We show that the temperature dependence of $\Delta(T)$ follows the expectation of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity, where $\Delta(0)/k_{B}T_{c}\approx1.72\pm 0.15$ and $\Delta(0)$ 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.