Quantum phase slips in a confined geometry

TL;DR

This paper investigates quantum phase slips in narrow, short superconducting films, revealing an exponential temperature dependence of resistance influenced by sample length, extending understanding to ultra-narrow wires.

Contribution

It demonstrates that in confined geometries, resistance behavior deviates from power-law to exponential dependence on temperature, highlighting the role of sample length and resistance.

Findings

Resistance is exponential in 1/T at low T and current.

The coefficient in the exponential depends on the sample's length or normal-state resistance.

Results apply to both short films and ultra-narrow wires, indicating a universal behavior.

Abstract

We consider tunneling of vortices across a superconducting film that is both narrow and short (and connected to bulk superconducting leads at the ends). We find that in the superconducting state the resistance, at low values of the temperature (T) and current, does not follow the power-law dependence on T characteristic of longer samples but is exponential in 1/T. The coefficient of 1/T in the exponent depends on the length or, equivalently, the total normal-state resistance of the sample. These conclusions persist in the one-dimensional limit, which is similar to the problem of quantum phase slips in an ultra-narrow short wire.