A study of Quantum Correlations in Open Quantum Systems

TL;DR

This paper investigates quantum correlations in two-qubit systems interacting with environments, analyzing entanglement dynamics and measures like Discord and Teleportation fidelity, revealing entangled states useful for teleportation despite Bell inequality violations.

Contribution

It provides a comparative analysis of quantum correlation measures in open quantum systems under different environmental interactions and identifies entangled states useful for teleportation without Bell inequality violation.

Findings

Entangled states can be useful for teleportation without violating Bell's inequality.

Quantum and classical correlations exhibit distinct dynamics under dissipative interactions.

Environmental parameters influence the nature and usefulness of quantum correlations.

Abstract

In this work, we study quantum correlations in mixed states. The states studied are modeled by a two-qubit system interacting with its environment via a quantum non demolition (purely dephasing) as well as dissipative type of interaction. The entanglement dynamics of this two qubit system is analyzed. We make a comparative study of various measures of quantum correlations, like Concurrence, Bell's inequality, Discord and Teleportation fidelity, on these states, generated by the above evolutions. We classify these evoluted states on basis of various dynamical parameters like bath squeezing parameter $r$, inter-qubit spacing $r_{12}$, temperature $T$ and time of system-bath evolution $t$. In this study, in addition we report the existence of entangled states which do not violate Bell's inequality, but can still be useful as a potential resource for teleportation. Moreover we study the dynamics of quantum as well as classical correlation in presence of dissipative coherence.