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Physical Review A

Nonequilibrium energy transport and nonclassical correlations of photons in a two-mode circuit quantum electrodynamic system

Xu-Min Chen, Y.D. Xu, Chen Wang

Published Oct 15, 2024• 0 citations
Publisher

Abstract

We investigate nonequilibrium energy transport and nonclassical correlations of photons in a nonequilibrium two-mode circuit quantum electrodynamic system with noncommutative qubit-photon couplings. Our calculations include a quantum master equation, which can handle ultrastrong qubit-photon interactions. For weak qubit-photon couplings, the nonmonotonic behavior of nonequilibrium energy flow is explored for large temperature bias, stemming from the breakdown of microscopic energy transition cycles. Two distinct scaling features of the coupling parameters in energy currents are analytically shown. Moreover, the longitudinal qubit-photon coupling shows a dramatic contribution to the exhibition of antibunching behaviors of autocorrelation and violation of the Cauchy-Schwarz inequality of the cross correlation of photons. These results may provide insight into quantum energy modulation devices and photon correlation manipulation in circuit quantum electrodynamics.

DOI
10.1103/physreva.110.043712

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Abstract The nonclassical feature of photons in the open finite-size Dicke model is investigated via the two-photon correlation function. The quantum dressed master equation combined with the extended coherent photonic states is applied to analyze the dissipative dynamics of both the photons and qubits. The antibunching to bunching transition of photons is clearly observed by tuning the qubit–photon coupling strength. The optimal qubit number is unraveled to enhance the two-photon correlation function. Moreover, the temperature bias of thermal baths induces significant two-photon bunching signature with deep strong qubit–photon interaction.