Two-dimensional superconducting state of monolayer Pb films grown on GaAs(110) in a strong parallel magnetic field

TL;DR

This study investigates monolayer Pb films on GaAs(110), revealing a 2D superconducting state resilient to high parallel magnetic fields, exceeding the Pauli limit, due to Rashba spin splitting effects.

Contribution

It provides experimental evidence of 2D superconductivity in monolayer Pb films with high magnetic field resilience, supporting theories of inhomogeneous states caused by Rashba spin splitting.

Findings

Superconducting transition temperature weakly depends on magnetic field up to 14 T.

Perpendicular magnetic field effects are unaffected by parallel field presence.

Superconductivity persists beyond the Pauli paramagnetic limit.

Abstract

Two dimensional (2D) superconductivity was studied by magnetotransport measurements on single-atomic-layer Pb films on a cleaved GaAs(110) surface. The superconducting transition temperature shows only a weak dependence on the parallel magnetic field up to 14 T, which is higher than the Pauli paramagnetic limit. Furthermore, the perpendicular magnetic field dependence of the sheet resistance is almost independent of the presence of the parallel field component. These results are explained in terms of an inhomogeneous superconducting state predicted for 2D metals with a large Rashba spin splitting.