Curvature-enhanced multipartite coherence in the multiverse

TL;DR

This paper investigates how quantum coherence in multipartite GHZ and W states behaves in a multiverse model with de Sitter spaces, revealing that curvature enhances coherence but diminishes quantum correlations, with potential implications for multiverse evidence.

Contribution

It introduces the study of multipartite quantum coherence in a multiverse setting, highlighting the contrasting effects of curvature on coherence and correlations, and establishing a distribution relationship for W states.

Findings

N-partite coherence increases with curvature in de Sitter spaces.

Curvature destroys quantum entanglement and discord.

Multipartite coherence may serve as evidence for the multiverse.

Abstract

Here, we study quantum coherence of N-partite GHZ (Greenberger-Horne-Zeilinger) and W states in the multiverse consisting of N causally disconnected de Sitter spaces. Interestingly, N-partite coherence increases monotonically as the curvature increases, while the Unruh effect destroys multipartite coherence in Rindler spacetime. Conversely, the curvature effect destroys quantum entanglement and discord, meaning that the curvature effect is beneficial to quantum coherence and harmful to quantum correlations in the multiverse. We find that, with the increase of n expanding de Sitter spaces, N-partite coherence of GHZ state increases monotonically for any curvature, while quantum coherence of the W state decreases or increases monotonically depending on the curvature. We find a distribution relationship, which indicates that the correlated coherence of N-partite W state is equal to the sum of all bipartite correlated coherence in the multiverse. Multipartite coherence exhibits unique properties in the multiverse, which argues that it may provide some evidence for the existence of the multiverse.