Anomalous Parallel Field Negative Magnetoresistance in Ultrathin Films Near the Superconductor-Insulator Transition

TL;DR

This paper reports the discovery of negative magnetoresistance in ultrathin amorphous bismuth films near the superconductor-insulator transition, linked to quantum fluctuations at the quantum critical point.

Contribution

It presents the first observation of anomalous negative magnetoresistance in ultrathin films near a quantum critical point, highlighting quantum fluctuations as the underlying cause.

Findings

Negative magnetoresistance observed in ultrathin bismuth films

Effect linked to quantum fluctuations of the order parameter

Signature of quantum criticality near the superconductor-insulator transition

Abstract

A parallel field negative magnetoresistance has been found in quench-condensed ultrathin films of amorphous bismuth in the immediate vicinity of the thickness-tuned superconductor-insulator transition. The effect appears to be a signature of quantum fluctuations of the order parameter associated with the quantum critical point.