Quantum phase slips in the presence of finite-range disorder

TL;DR

This paper investigates how finite-range disorder affects quantum phase slips in superconducting wires, revealing a transition influenced by the wire's plasmon impedance and mapping the problem onto dissipative quantum mechanics.

Contribution

It introduces a first-principles instanton approach to analyze disorder effects on QPS, identifying a superconductor-insulator transition controlled by plasmon impedance.

Findings

Superconductor-insulator transition at Z=6.5 kOhm

Disorder modeled as finite-range affects QPS rate

System maps onto dissipative quantum mechanics

Abstract

To study the effect of disorder on quantum phase slips (QPS) in superconducting wires, we consider the plasmon-only model where disorder can be incorporated into a first-principles instanton calculation. We consider weak but general finite-range disorder and compute the formfactor in the QPS rate associated with momentum transfer. We find that the system maps onto dissipative quantum mechanics, with the dissipative coefficient controlled by the wave (plasmon) impedance Z of the wire and with a superconductor-insulator transition at Z=6.5 kOhm. We speculate that the system will remain in this universality class after resistive effects at the QPS core are taken into account.