Current Noise Investigation in Josephson Devices by Switching Current Measurements

TL;DR

This paper investigates the critical current noise in niobium Josephson junctions using switching current measurements, revealing linear white noise behavior related to junction area and temperature, which informs the understanding of intrinsic noise in quantum devices.

Contribution

It introduces a measurement technique for analyzing critical current noise in Josephson junctions and characterizes its dependence on area and temperature.

Findings

White noise scales linearly with junction area and temperature

Critical current noise measurement technique is effective

Provides insights into intrinsic noise of Josephson devices

Abstract

An experimental investigation of the critical current noise in underdamped niobium based Josephson junctions by a technique based on the switching current measurements is reported. By sweeping the junction with a current ramp we measure the critical current switching using the standard time of flight technique and analyze the data to extract the current noise. The experimental results show a linear behavior of the current white noise from both the junction area and the temperature. These measurement provide very useful information about the intrinsic noise of Josephson devices involving SQUIDs and qubits.