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

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.