Switching Current Distributions in Josephson Junctions at Very Low Temperatures

TL;DR

This paper revises Kramers' theory to accurately describe switching current distributions in Josephson junctions at millikelvin temperatures, aligning theory with experimental data.

Contribution

A simple modification to Kramers' theory is proposed, improving its applicability to low-temperature Josephson junction switching experiments.

Findings

Revised theory matches experimental distributions accurately.

Standard Kramers' theory underestimates escape rates at millikelvin temperatures.

Enhanced understanding of quantum effects in Josephson junction switching.

Abstract

Swept bias experiments carried out on Josephson junctions yield the distributions of the probabilities of early switching from the zero voltage state. Kramers' theory of thermally activated escape from a one-dimensional potential is well known to fall short of explaining such experiments when the junctions are at millikelvin temperatures. We propose a simple revision of the theory which is shown to yield extremely good agreement with experimental data.