Rashba effect and critical field of atomic-layer superconductor Si(111)-(√7×√3)-In

Abstract

Si(111)-(√7×√3)-In is an atomic-layer superconductor with a critical temperature of 3 K. Our low-temperature electron transport measurements strongly suggests that the parallel upper critical field exceeds the paramagnetic limit expected for a conventional superconductor. We investigate the mechanism based on the pair-breaking theory for a superconductor in the presence of both the Rashba effect and elastic scattering, utilizing the information of the band structure obtained from density functional theory calculations.