Tripartite Entanglements in Non-inertial Frames

TL;DR

This paper investigates how the Unruh effect influences tripartite entanglement in quantum states, revealing differences between fermionic and bosonic states and showing that entanglement can persist or vanish depending on the state and observer acceleration.

Contribution

It provides a detailed analysis of tripartite entanglement degradation in non-inertial frames, highlighting differences between GHZ and W states and the asymmetric entanglement distribution among parts.

Findings

Fermionic states retain some entanglement even at infinite acceleration.

Bosonic states' entanglement vanishes asymptotically with acceleration.

Bipartite entanglement behaves differently in GHZ and W states.

Abstract

Entanglement degradation caused by the Unruh effect is discussed for the tripartite GHZ or W states constructed by modes of a non-interacting quantum field viewed by one inertial observer and two uniformly accelerated observers. For fermionic states, the Unruh effect even for infinite accelerations cannot completely remove the entanglement. However, for the bosonic states, the situation is different and the entanglement vanishes asymptotically. Also, the entanglement is studied for the bipartite subsystems. While for the GHZ states all the bipartite subsystems are identically disentangled, for the W states the bipartite subsystems are somewhat entangled, though, this entanglement can be removed for appropriately accelerated observers. Interestingly, logarithmic negativity as a measure for determining the entanglement of one part of the system relative to the other two parts, is not generally the same for different parts. This means that we encounter tripartite systems where each part is differently entangled to the other two parts.