Universal conductance of nanowires near the superconductor-metal quantum transition

TL;DR

This paper studies the universal conductance behavior of nanowires near a quantum phase transition between superconducting and metallic states, revealing universal properties influenced by lead configurations and phase slips.

Contribution

It introduces a critical theory framework that predicts universal conductance behavior in nanowires near the superconductor-metal transition, accounting for different lead types.

Findings

Universal frequency, temperature, and length dependence of conductance.

Universal d.c. conductance in SN wires independent of length at low temperatures.

Critical theory includes quantum and thermal phase slips.

Abstract

We consider wires near a zero temperature transition between superconducting and metallic states. The critical theory obeys hyperscaling, which leads to a universal frequency, temperature, and length dependence of the conductance; quantum and thermal phase slips are contained within this critical theory. Normal (NN), superconducting (SS) and mixed (SN) leads on the wire determine distinct universality classes. For the SN case, wires near the critical point have a universal d.c. conductance which is independent of the length of the wire at low temperatures.