High resolution measurements of the switching current in a Josephson tunnel junction: Thermal activation and macroscopic quantum tunneling

TL;DR

This paper introduces a high-resolution measurement scheme for the switching current distribution in Josephson tunnel junctions, enabling detailed analysis of thermal activation and quantum tunneling phenomena crucial for quantum computing applications.

Contribution

The authors developed an optically decoupled timing measurement technique that significantly improves resolution in studying Josephson junction switching currents.

Findings

Successful measurement of thermal activation effects.

Observation of macroscopic quantum tunneling.

Potential for improved characterization in quantum devices.

Abstract

We have developed a scheme for a high resolution measurement of the switching current distribution of a current biased Josephson tunnel junction using a timing technique. The measurement setup is implemented such that the digital control and read-out electronics are optically decoupled from the analog bias electronics attached to the sample. We have successfully used this technique to measure the thermal activation and the macroscopic quantum tunneling of the phase in a small Josephson tunnel junction with a high experimental resolution. This technique may be employed to characterize current-biased Josephson tunnel junctions for applications in quantum information processing.