Fluctuation conductivity of thin films and nanowires near a parallel-field-tuned superconducting quantum phase transition

TL;DR

This paper analyzes quantum fluctuation effects on conductivity near a magnetic-field-induced superconducting quantum phase transition in thin films and nanowires, revealing three distinct regimes with different temperature and field behaviors.

Contribution

It provides a detailed calculation of fluctuation corrections to conductivity near the quantum critical point, highlighting the interplay of various fluctuation contributions at zero temperature.

Findings

Total quantum fluctuation correction is negative at zero temperature.

Identifies three regimes with distinct temperature and field dependencies.

Results are experimentally accessible in thin film and nanowire systems.

Abstract

We calculate the fluctuation correction to the normal state conductivity in the vicinity of a quantum phase transition from a superconducting to normal state, induced by applying a magnetic field parallel to a dirty thin film or a nanowire with thickness smaller than the superconducting coherence length. We find that at zero temperature, where the correction comes purely from quantum fluctuations, the positive Aslamazov-Larkin contribution, the negative density of states contribution, and the Maki-Thompson interference contribution, are all of the same order and the total correction is negative. Further we show that based on how the quantum critical point is approached, there are three regimes that show different temperature and field dependencies which should be experimentally accessible.