Superconductivity in an Aluminum Film Grown by Molecular Beam Epitaxy

Abstract

We report on superconductivity in an aluminum film grown on a GaAs substrate by molecular beam epitaxy (MBE). We show that the quality of the MBE-grown sample is better than that of its counterpart prepared by electron gun evaporation. This is evidenced by the observed much lower resistivity, higher critical current, longer coherence length, and downward critical field-temperature characteristic H-c(T). Our results suggest that a MBE-grown Al thin film can be used to study superconductivity in a relatively clean metal.