Entanglement harvesting in cosmic string spacetime

TL;DR

This paper explores how cosmic strings influence entanglement harvesting between static detectors, revealing that the string's conical geometry can both enhance and hinder entanglement depending on detector placement.

Contribution

It provides a detailed analysis of entanglement harvesting in cosmic string spacetime, highlighting how the conical structure affects entanglement range and strength for different detector alignments.

Findings

Cosmic strings can both aid and hinder entanglement harvesting.

Detectors on opposite sides of the string harvest more entanglement than in flat spacetime.

The presence of a cosmic string affects the harvesting range differently based on detector alignment.

Abstract

We investigate the entanglement harvesting phenomenon for static detectors that locally interact with massless scalar fields in the cosmic string spacetime, which, though locally flat, features a conical structure defined by a deficit angle. Specifically, we analyze three detector alignments relative to the string: parallel and orthogonal alignments with detectors on the same side of the string, and an orthogonal alignment with detectors on opposite sides of the string. For the alignments on the same side of the string, we observe that the cosmic string's presence can either aid or hinder entanglement harvesting, affecting both the extent of entanglement harvested and the achievable range of interdetector separation. This effect depends on the distance between the detectors and the string and differs markedly from scenarios in a locally flat spacetime with a reflecting boundary, where the boundary invariably extends the harvesting-achievable range. Conversely, for the alignment with detectors on opposite sides of the string, we find that detectors consistently harvest more entanglement than those in a flat spacetime devoid of a cosmic string. This starkly contrasts the behavior observed with detectors on the same side. Interestingly, the presence of a cosmic string expands the harvesting-achievable range for detectors in orthogonal alignment only when near the string, whereas it invariably reduces the achievable range for detectors in parallel alignment.