Deterministic phase slips in mesoscopic superconducting rings

TL;DR

This study provides a detailed, quantitative understanding of phase slips in mesoscopic superconducting rings, showing that they occur deterministically when the free energy barrier vanishes, aligning experimental data with Ginzburg-Landau theory.

Contribution

The paper demonstrates a precise match between experimental measurements and Ginzburg-Landau theory, revealing deterministic phase slips and clarifying the free energy landscape in one-dimensional superconductors.

Findings

Agreement between measurements and Ginzburg-Landau theory over various conditions

Phase slips occur deterministically when the energy barrier disappears

Provides a framework for studying quantum and thermal phase slips

Abstract

The properties of one-dimensional superconductors are strongly influenced by topological fluctuations of the order parameter, known as phase slips, which cause the decay of persistent current in superconducting rings and the appearance of resistance in superconducting wires. Despite extensive work, quantitative studies of phase slips have been limited by uncertainty regarding the order parameter's free energy landscape. Here we show detailed agreement between measurements of the persistent current in isolated flux-biased rings and Ginzburg-Landau theory over a wide range of temperature, magnetic field, and ring size; this agreement provides a quantitative picture of the free energy landscape. We also demonstrate that phase slips occur deterministically as the barrier separating two competing order parameter configurations vanishes. These results will enable studies of quantum and thermal phase slips in a well-characterized system and will provide access to outstanding questions regarding the nature of one-dimensional superconductivity.