Energy and information propagation in a finite coupled bosonic heat bath

TL;DR

This paper investigates how energy and information transfer between a harmonic oscillator and a finite bosonic heat bath, revealing different dissipative behaviors depending on the resonance condition, and linking non-Markovianity to correlation dynamics.

Contribution

It provides a detailed analysis of energy and information propagation in a finite bosonic heat bath, highlighting the role of resonance and correlations in non-Markovian dynamics.

Findings

Resonance leads to free propagation and pure dissipation.

Far detuning results in almost unitary evolution with limited correlations.

Intermediate detuning causes oscillatory behavior and non-Markovian effects.

Abstract

The finite coupled bosonic model of reservoir introduced by Vasile et al. [1] to characterize non-Markovianity, is used to study the different dissipative behaviors of a harmonic oscillator coupled to it when it is in resonance, close to resonance or far detuned. We show that information and energy exchange between system and heat bath go hand in hand because phonons are the carriers of both: in resonance free propagation of excitations is achieved, and therefore pure dissipation, while when far detuned the system can only correlate with the first oscillator in the bath's chain, leading to almost unitary evolution. In the intermediate situation we show the penetration of correlations and the formation of oscillatory (dressed state) behavior, which lies at the root of non-Markovianity.