Does acceleration always degrade quantum entanglement for tetrapartite Unruh-DeWitt detectors?

TL;DR

This paper reveals that the Unruh effect can both degrade and enhance quantum entanglement in tetrapartite Unruh-DeWitt detectors, challenging the traditional view of its solely destructive role.

Contribution

It demonstrates that the Unruh effect has a dual role, sometimes increasing entanglement in multipartite states, which is a novel insight compared to prior bipartite studies.

Findings

Entanglement first decreases then increases with acceleration.

Unruh effect can enhance quantum entanglement under certain conditions.

Challenges the view that Unruh effect always destroys entanglement.

Abstract

Previous studies have shown that the Unruh effect completely destroys quantum entanglement and coherence of bipartite states, as modeled by entangled Unruh-DeWitt detectors. But does the Unruh effect have a different impact on quantum entanglement of multipartite states within this framework? In this paper, we investigate the influence of the Unruh effect on $1-3$ entanglement in the context of entangled tetrapartite Unruh-DeWitt detectors. We find that quantum entanglement of tetrapartite $W$ state first decreases to a minimum value and then increases to a fixed value with the growth of the acceleration. This indicates that the Unruh effect can, under certain conditions, enhance quantum entanglement. In other words, the Unruh effect plays a dual role in the behavior of quantum entanglement-both diminishing and enhancing it. This discovery challenges and overturns the traditional view that the Unruh effect is solely detrimental to quantum entanglement and coherence in entangled Unruh-DeWitt detectors, offering a fresh and profound perspective on its impact.