Low temperature magnetoresistance of dirty thin films and quantum wires near a parallel-field-tuned superconducting quantum phase transition

TL;DR

This paper investigates how superconducting fluctuations affect the low temperature magnetoresistance in dirty thin films and wires near a quantum phase transition, revealing non-monotonic behavior due to competing effects.

Contribution

It provides a detailed analysis of superconducting fluctuation corrections to conductivity near a quantum phase transition in low-dimensional systems.

Findings

Superconducting fluctuation corrections are of the same order at zero temperature.

Negative magnetoresistance occurs in the quantum regime.

Non-monotonic magnetoresistance is predicted at higher temperatures.

Abstract

We study the low temperature magnetoresistance of dirty thin films and quantum wires close to a quantum phase transition from a superconducting to normal state, induced by applying a parallel magnetic field. We find that the different corrections (Aslamazov-Larkin, density of states and Maki-Thompson) to the normal state conductivity, coming from the superconducting pair fluctuations, are of the same order at zero temperature. There are three regimes at finite temperatures. In the "quantum" regime, which essentially shows a zero-temperature-like behavior we find a negative magnetoresistance. Since in the "classical" regime the correction is positive, we predict a non-monotonic magnetoresistance at higher temperatures.