Continuous variable methods in relativistic quantum information: Characterisation of quantum and classical correlations of scalar field modes in noninertial frames

TL;DR

This paper introduces a unified method using Renyi-2 entropy to quantify correlations in Gaussian states of scalar fields, analyzing how acceleration affects quantum and classical correlations due to the Unruh effect.

Contribution

It presents a new analytical approach for quantifying correlations in scalar field modes, including bipartite and multipartite entanglement, in noninertial frames.

Findings

Quantum and classical correlations degrade differently under acceleration.

Residual quantum discord can survive infinite acceleration if measured by an inertial observer.

Abstract

We review a recently introduced unified approach to the analytical quantification of correlations in Gaussian states of bosonic scalar fields by means of Renyi-2 entropy. This allows us to obtain handy formulae for classical, quantum, total correlations, as well as bipartite and multipartite entanglement. We apply our techniques to the study of correlations between two modes of a scalar field as described by observers in different states of motion. When one or both observers are in uniform acceleration, the quantum and classical correlations are degraded differently by the Unruh effect, depending on which mode is detected. Residual quantum correlations, in the form of quantum discord without entanglement, may survive in the limit of an infinitely accelerated observer Rob, provided they are revealed in a measurement performed by the inertial Alice.