Capacitively Enhanced Thermal Escape in Underdamped Josephson Junctions

TL;DR

This paper investigates how capacitance influences thermal escape in underdamped Josephson junctions, revealing that shunted junctions maintain thermal activation up to higher temperatures compared to unshunted ones.

Contribution

It provides experimental insights into the role of capacitance in thermal escape dynamics of Josephson junctions, highlighting differences between shunted and unshunted configurations.

Findings

Shunted junctions preserve thermal activation up to higher temperatures.

Unshunted junctions show phase diffusion at elevated temperatures.

Experimental results align with standard thermal activation theory for shunted junctions.

Abstract

We have studied experimentally the escape dynamics in underdamped capacitively shunted and unshunted Josephson junctions with submicroampere critical currents below 0.5 K temperatures. In the shunted junctions, thermal activation process was preserved up to the highest temperature where the escape in the unshunted junctions exhibits the phase diffusion. Our observations in the shunted junctions are in good agreement with the standard thermal activation escape, unlike the results in the unshunted junctions.