Quantum discord between relatively accelerated observers

TL;DR

This paper investigates how quantum correlations, measured by quantum discord, persist between two scalar field modes when one observer accelerates, revealing non-zero quantum correlations even under extreme acceleration conditions.

Contribution

It demonstrates that quantum discord remains finite between accelerated observers despite the absence of entanglement, highlighting the robustness of quantum correlations beyond entanglement.

Findings

Quantum discord persists without entanglement under acceleration.

Quantum correlations remain non-zero even at infinite acceleration.

Potential for quantum advantages using discord in relativistic settings.

Abstract

We calculate the quantum discord between two free modes of a scalar field which start in a maximally entangled state and then undergo a relative, constant acceleration. In a regime where there is no distillable entanglement due to the Unruh effect, we show that there is a finite amount of quantum discord, which is a measure of purely quantum correlations in a state, over and above quantum entanglement. Even in the limit of infinite acceleration of the observer detecting one of the modes, we provide evidence for a non-zero amount of purely quantum correlations, which might be exploited to gain non-trivial quantum advantages.