Negative Magneto-Resistance in a Long Superconducting Wires: Theory and Experiments

TL;DR

This paper presents a theoretical model explaining negative magnetoresistance in thin superconducting wires, supported by experimental data showing good agreement, highlighting the competing effects of order parameter fluctuations and quasiparticle charge imbalance.

Contribution

It introduces a simple analytical formula capturing negative magnetoresistance due to thermodynamic and quantum fluctuations in superconducting wires, validated by experiments.

Findings

Analytical formula matches experimental data

Negative magnetoresistance arises from quasiparticle charge imbalance

Positive and negative contributions compete in the magnetoresistance mechanism

Abstract

The effect of negative magnetoresistance for thin superconducting wire was considered in a simple model. These phenomena originated from competition of two mechanism: fluctuations of the order parameter and quasiparticles charge imbalance which accompanies each phase slip event. First process results in conventional positive magnetoresistance while the second mechanism gives the negative contributions. Simple analytical formula is obtained for the negative magnetic resistance caused by both the thermodynamics (TAPS) and quantum fluctuations. Theoretical results are compared with experimental data and demonstrate good agreement between theory and experiment.