Coherence Dynamics of Two Interacting Bosonic Modes in a Thermal Environment

Aurelian Isar,Gh Adam,M Hnatič,J Buša

doi:10.1051/epjconf/202022601006

Abstract

We describe the time evolution of the quantum coherence in an open system consisting of two coupled bosonic modes embedded in a thermal reservoir. We discuss the influence of the environment in terms of the covariance matrix for initial squeezed thermal states. The coherence is quantified using the relative entropy as a measure, and its dynamics is studied in the framework of the theory of open systems based on completely positive quantum dynamical semigroups. We show that the evolution of the quantum coherence strongly depends on the initial state of the system (squeezing parameter and thermal photon numbers), the parameters characterizing the thermal reservoir (temperature and dissipation coefficient) and the intensity of the coupling between the two modes.

Highlights

Quantum coherence arises from the superposition principle, which represents the essential point of departure of quantum physics from the classical views of the reality
In order to study the dynamics of the subsystem consisting of two coupled bosonic modes weakly interacting with a thermal reservoir, we use the axiomatic formalism based on completely positive quantum dynamical semigroups
We have investigated the Markovian evolution of the quantum coherence of a system composed of two coupled bosonic modes embedded in a thermal environment using the axiomatic formalism based on completely positive quantum dynamical semigroups

Summary

Introduction

Quantum coherence arises from the superposition principle, which represents the essential point of departure of quantum physics from the classical views of the reality. In the framework of the theory of open systems, the dynamics of quantum correlations of two, both uncoupled and coupled, bosonic modes embedded in a common thermal bath, for initial Gaussian states of the system [24,25,26,27,28,29,30]. In this work we use the axiomatic formalism of the theory of open quantum systems based on completely positive dynamical semigroups [31] to address the quantification of the coherence, following Ref.

Master equation for two bosonic modes interacting with the environment

Coherence of Gaussian states

Time evolution of the quantum coherence

Summary and conclusions