Extraction of entanglement from quantum fields with entangled particle detectors

TL;DR

This paper investigates how entangled particle detectors interact with quantum fields, revealing conditions under which entanglement is extracted, enhanced, or degraded, especially in curved spacetime with gravitational shockwaves.

Contribution

It introduces a detailed analysis of entanglement dynamics between initially entangled detectors interacting with quantum fields, including effects of gravitational shockwaves.

Findings

Weakly correlated detectors can gain entanglement from the field.

Strongly entangled detectors experience entanglement degradation.

Shockwaves can enhance entanglement and increase effective detector separation.

Abstract

We consider two initially entangled Unruh-DeWitt particle detectors and examine how the initial entanglement changes after interacting with a quantum scalar field. As initially nonentangled detectors extract entanglement from the field, entangled detectors also can gain more entanglement so long as they are weakly correlated at the beginning. For initially sufficiently entangled detectors, only degradation takes place. We then apply our analysis to a gravitational shockwave spacetime and show that a shockwave could enhance the initial entanglement of weakly entangled detectors. Moreover, we find that this enhancement can occur for greater detector separations than in Minkowski spacetime.