Exact non-Markovian cavity dynamics strongly coupled to a reservoir

TL;DR

This paper provides an exact analytical study of non-Markovian dynamics in a strongly coupled microcavity-reservoir system, revealing how memory effects influence coherence, thermal behavior, and dissipation in the cavity.

Contribution

It derives an exact master equation solution for the cavity's non-Markovian dynamics at arbitrary temperature, highlighting the role of Green functions and the impact of strong coupling.

Findings

Non-Markovian memory effects significantly alter cavity coherence and thermal dynamics.

Strong coupling leads to long-time dissipationless evolution of the cavity field.

Memory effects induce a critical transition in noise dynamics from weak to strong coupling.

Abstract

The exact non-Markovian dynamics of a microcavity strongly coupled to a general reservoir at arbitrary temperature is studied. With the exact master equation for the reduced density operator of the cavity system, we analytically solve the time evolution of the cavity state and the associated physical observables. We show that the non-Markovian dynamics is completely determined by the propagating (retarded) and correlation Green functions. Compare the non-Markovian behavior at finite temperature with those at zero-temperature limit or Born-Markov limit, we find that the non-Markovian memory effect can dramatically change the coherent and thermal dynamics of the cavity. We also numerically study the dissipation dynamics of the cavity through the mean mode amplitude decay and the average photon number decay in the microwave regime. It is shown that the strong coupling between the cavity and the reservoir results in a long-time dissipationless evolution to the cavity field amplitude, and its noise dynamics undergoes a critical transition from the weak to strong coupling due to the non-Markovian memory effect.