Hall conductivity dominated by fluctuations near the superconducting transition in disordered films

TL;DR

This study investigates the Hall effect in disordered tantalum nitride films, revealing a significant fluctuation-induced contribution near the superconducting transition that extends to high temperatures and magnetic fields, aligning with theoretical predictions.

Contribution

It provides experimental evidence linking superconducting fluctuations to Hall conductivity in disordered films, confirming recent theoretical models.

Findings

Large fluctuation contribution to Hall conductivity near $T_c$

Fluctuation effects extend above $T_c$ and $H_{c2}(0)$

Quantitative agreement with time-dependent Ginzburg-Landau theory

Abstract

We have studied the Hall effect in superconducting tantalum nitride films. We find a large contribution to the Hall conductivity near the superconducting transition, which we can track to temperatures well above $T_c$ and magnetic fields well above the upper critical field, $\text{\text{H}}_{c2}(0)$. This contribution arises from Aslamazov-Larkin superconducting fluctuations, and we find quantitative agreement between our data and recent theoretical analysis based on time dependent Ginzburg-Landau theory.