Role of initial system-environment correlations: A master equation approach

TL;DR

This paper develops a master equation that explicitly accounts for initial system-environment correlations and demonstrates their impact on the dynamics of quantum systems, especially in the context of many two-level atoms.

Contribution

It introduces a new master equation framework that incorporates initial correlations, providing insights into their effects on quantum system evolution.

Findings

Initial correlations can accelerate quantum state evolution.

The influence of state preparation depends on initial states.

Correlations significantly affect dynamics in quantum open systems.

Abstract

In order to achieve practical implementations of emerging quantum technologies, it is important to have a firm understanding of the dynamics of realistic quantum open systems. Master equations provide a widely used tool in this regard. In this work, we first construct a master equation, valid for weak system-environment coupling, which explicitly takes into account the impact of preparing an initial system state from an equilibrium system-environment state that has system-environment correlations. We then investigate the role of initial system-environment correlations using this master equation for a system consisting of many two-level atoms interacting with a common environment. We show that, in general, due to the initial system-environment correlations before a state preparation, the quantum state of the system can evolve at a faster time-scale. Moreover, we also consider different initial state preparations, and demonstrate that the influence of state preparations depends on the initial states prepared. Our results can be of interest to many topics based on quantum open systems where system-environment correlation effects have been neglected before.