Landau-Zener tunnelling in dissipative circuit QED

TL;DR

This paper studies how temperature and dissipation affect Landau-Zener tunnelling in circuit QED, revealing non-monotonic behaviors and providing numerical and analytical insights into the transition probabilities.

Contribution

It introduces a phase-space numerical method within Bloch-Redfield theory to analyze dissipative effects on Landau-Zener transitions in circuit QED.

Findings

Spin-flip probability varies non-monotonically with temperature and dissipation.

Numerical results are reliable even at low temperatures.

Analytical solutions complement numerical findings for specific limits.

Abstract

We investigate the influence of temperature and dissipation on the Landau-Zener transition probability in circuit QED. Dissipation is modelled by coupling the transmission line to a bath of harmonic oscillators. The reduced description for the density operator is treated within Bloch-Redfield theory. A phase-space representation allows an efficient numerical implementation of the resulting master equation. It provides reliable results which are valid even for rather low temperatures. We find that the spin-flip probability as a function of temperature and dissipation strength exhibits a non-monotonic behaviour. Our numerical results are complemented by analytical solutions for zero temperature and for vanishing dissipation strength.