Entanglement trapping in a non-stationary structured reservoir

TL;DR

This paper investigates how a two-level atom interacts with a structured reservoir featuring a frequency gap, leading to entanglement trapping and revealing dynamic reservoir spectra in the long-term weak coupling regime.

Contribution

It introduces a pseudomodes approach to analyze entanglement trapping in non-stationary structured reservoirs, highlighting novel reservoir dynamics.

Findings

Entanglement persists between atom and reservoir modes in trapping states.

Strong correlations are observed during entanglement trapping.

Reservoir spectrum varies over time in the long-term weak coupling limit.

Abstract

We study a single two-level atom interacting with a reservoir of modes defined by a reservoir structure function with a frequency gap. Using the pseudomodes technique, we derive the main features of a trapping state formed in the weak coupling regime. Utilising different entanglement measures we show that strong correlations and entanglement between the atom and the modes are in existence when this state is formed. Furthermore, an unexpected feature for the reservoir is revealed. In the long time limit and for weak coupling the reservoir spectrum is not constant in time.