Non-Markovian decoherence dynamics of the hybrid quantum system with a cavity strongly coupling to a spin ensemble: a master equation approach

TL;DR

This paper uses an exact master equation approach to analyze non-Markovian decoherence in a hybrid quantum system with a superconducting cavity strongly coupled to NV center spin ensembles, revealing mechanisms for decoherence suppression and quantum memory effects.

Contribution

It introduces an exact master equation method to model non-Markovian decoherence in a strongly coupled cavity-spin system, explaining experimental results and decoherence suppression mechanisms.

Findings

Decoherence is suppressed in the strong-coupling regime.

Spectral hole burning creates localized states that reduce decoherence.

Quantum fluctuations demonstrate quantum memory effects.

Abstract

Based on the recent experiments on the hybrid quantum system of a superconducting microwave cavity coupling strongly to an inhomogeneous broadening spin ensemble under an external driving field, we use the exact master equation approach to investigate its non-Markovian decoherence dynamics. Here the spin ensemble is made by negatively charged nitrogen-vacancy (NV) defects in diamond. Our exact master equation theory for open systems depicts the experimental decoherence results and reveals the mechanism how the decoherence induced by the inhomogeneous broadening is suppressed in the strong-coupling regime. Moreover, we show how the spectral hole burning generates localized states to further suppress the cavity decoherence. We also investigate the two-time correlations in this system to further show how quantum fluctuations manifest quantum memory.