Quantum Jump Approach to Switching Process of a Josephson Junction Coupled to a Microscopic Two-Level System

TL;DR

This paper models the random switching behavior of a Josephson junction coupled to a two-level system using a quantum jump approach, aligning well with experimental results and offering insights into macroscopic quantum jumps.

Contribution

It introduces a quantum jump modeling framework for Josephson junctions coupled to two-level systems, providing a new physical understanding of their switching dynamics.

Findings

Theoretical results match experimental observations.

Quantum jumps reveal microscopic two-level structures.

Model offers a new tool for solid-state quantum investigations.

Abstract

With microwave irradiation, the switching current of a Josephson junction coupled to a microscopic two-level system jumps randomly between two discrete states. We modeled the switching process of the coupled system with quantum jump approach that was generally used in quantum optics. The parameters that affect the character of the quantum jumps between macroscopic quantum states are discussed. The results obtained from our theoretical analysis agree well with those of the experiments and provide a clear physical picture for the macroscopic quantum jumps in Josephson junctions coupled with two-level systems. In addition, quantum jumps may serve as a useful tool to investigate the microscopic two-level structures in solid-state systems.