Non-classical correlations in non-Markovian continuous variable systems

TL;DR

This paper investigates how non-Markovian environments affect quantum correlations like entanglement and discord in two harmonic oscillators, revealing environment-induced quantum discord creation and robustness hierarchies.

Contribution

It provides a detailed analysis of non-Markovian effects on quantum correlations in continuous variable systems, highlighting environment-induced discord and robustness hierarchies.

Findings

Environment degrades correlations in independent baths

Quantum discord can be generated in common baths

Entanglement remains absent in uncorrelated initial states

Abstract

We consider two identical and non-interacting harmonic oscillators coupled to either two independent bosonic baths or to a common bosonic bath. Under the only assumption of weak coupling, we analyze in details the non-Markovian short time-scale evolution of intensity correlations, entanglement and quantum discord for initial two-mode squeezed-thermal vacuum states. In the independent reservoirs case we observe the detrimental effect of the environment for all these quantities and we establish a hierarchy for their robustness against the environmental noise. In the common reservoir case, for initial uncorrelated states, we find that only quantum discord can be created via interaction with the bath, while entanglement and sub shot noise intensity correlations remain absent.