Upper critical field in electron-doped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$: two-gap model

TL;DR

This study investigates the upper critical magnetic field in electron-doped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_{4+eta}$ using resistivity measurements, revealing that a two-gap model explains the data in the dirty limit.

Contribution

It provides experimental resistivity data and confirms that a two-gap model accurately describes the upper critical field in this superconductor.

Findings

Data fits well with a two-band/two-gap model

Superconductor behaves in the dirty limit

Upper critical field phase diagram characterized down to 0.4 K

Abstract

We present resistivity measurements of the upper critical field (H$_{c2}$) phase diagram as a function of temperature (T) for Nd$_{1.85}$Ce$_{0.15}$CuO$_{4+\delta}$/SrTiO$_3$ single crystal films with different degree of disorder ($\delta$) in magnetic fields up to 90 kOe at temperatures down to 0.4 K. The data are well described by a two-band/two-gap model for a superconductor in the dirty limit.