Escape from a zero current state in a one dimensional array of Josephson junctions

TL;DR

This paper investigates the switching voltage and escape rates in a one-dimensional Josephson junction array, revealing temperature-dependent behavior and a transition to temperature-independent escape at low temperatures.

Contribution

It provides experimental histograms and theoretical analysis of escape rates without assuming the barrier shape, highlighting two distinct temperature regimes.

Findings

Switching voltage Vsw varies with temperature.

High-temperature escape explained by Kramers model.

Low-temperature escape becomes temperature-independent.

Abstract

A long one dimensional array of small Josephson junctions exhibits Coulomb blockade of Cooper pair tunneling. This zero current state exists up to a switching voltage, Vsw, where there is a sudden onset of current. In this paper we present histograms showing how Vsw changes with temperature for a long array and calculations of the corresponding escape rates. Our analysis of the problem is based on the existence of a voltage dependent energy barrier and we do not make any assumptions about its shape. The data divides up into two temperature regimes, the higher of which can be explained with Kramers thermal escape model. At low temperatures the escape becomes independent of temperature.