Pair-Breaking and Dimensionality in Spin-Orbit Coupled Superconductors

TL;DR

This paper investigates how various depairing mechanisms affect superconductivity in ultra-thin LaBi2 films, providing new insights into the roles of spin exchange, paramagnetic, and orbital effects.

Contribution

It introduces a comprehensive analysis of thickness-dependent superconductivity using the multi-mechanism framework, highlighting the importance of spin exchange scattering.

Findings

Resolved field-enhanced superconductivity in the thin limit.

Estimated the role of spin exchange scattering alongside paramagnetic and orbital effects.

Recast how scattering times influence critical temperature and Pauli limit in 2D superconductors.

Abstract

The response of ultra-thin superconducting materials under parallel magnetic fields is often leveraged to obtain insight into the nature of the condensate, including features attributable to unconventional forms of pairing. Despite there being multiple competing mechanisms responsible for suppressing superconductivity, it is common for these analyses to overlook certain depairing channels. Here we report an analysis of thickness dependent superconductivity in thin films of \ce{LaBi2} using the multi-mechanism Kharitonov-Feigel'man framework . By resolving field-enhanced superconductivity in the thin-limit, we obtain an estimate the role of spin exchange scattering, in addition to paramagnetic and orbital effects. Our analyses offer insight into how fundamental quantities such as the critical temperature as well as Pauli limit are defined, recasting the landscape for how scattering times in two-dimensional superconductors can be interpreted.