Superconductor insulator transition in thin films driven by an orbital parallel magnetic field effect

TL;DR

This paper presents a theoretical study of how a parallel magnetic field affects disordered superconducting films, showing that orbital effects can induce a superconductor-insulator transition consistent with experimental observations.

Contribution

The paper introduces a microscopic model highlighting the orbital mechanism of magnetic field-induced transitions in disordered superconducting films, aligning with recent experimental data.

Findings

Critical magnetic field decreases with sheet resistance.

Orbital effects can drive superconductor-insulator transition.

Experimental results favor orbital over spin mechanisms.

Abstract

We study theoretically orbital effects of a parallel magnetic field applied to a disordered superconducting film. We find that the field reduces the phase stiffness and leads to strong quantum phase fluctuations driving the system into an insulating behavior. This microscopic model shows that the critical field decreases with the sheet resistance, in agreement with recent experimental results. The predictions of this model can be used to discriminate spin and orbital effects. We find that experiments conducted by A. Johansson \textit{et al.} are more consistent with the orbital mechanism.