Time-domain measurements of quasiparticle tunneling rates in a single-Cooper-pair transistor

TL;DR

This paper reports real-time measurements of quasiparticle tunneling rates in a single-Cooper-pair transistor using rf reflectometry, analyzing dwell times to understand temperature and gate dependence of these rates.

Contribution

It introduces a method for direct, real-time measurement of quasiparticle tunneling rates in a single-Cooper-pair transistor, including analysis techniques and dependence on temperature and gate voltage.

Findings

Measured even-to-odd and odd-to-even tunneling rates directly

Analyzed dwell time distributions to extract transition rates

Reported on temperature and gate voltage dependence of tunneling rates

Abstract

We have measured, in real time, individual quasiparticle tunneling in a single Cooper pair transistor, using rf reflectometry on the supercurrent branch. We have extracted the even-to-odd and odd-to-even transition rates directly by analyzing the distributions of dwell times in the even and odd states of the transistor. We discuss both the measurement and analysis techniques and report on the temperature and gate dependence of the quasiparticle tunneling rates.