How measuring a quantum field affects entanglement harvesting

TL;DR

This paper investigates how performing measurements on a quantum field influences the entanglement harvesting process, revealing regimes where measurements can either preserve, degrade, or enhance entanglement extraction.

Contribution

It introduces a model for field measurements via detector coupling and analyzes their impact on entanglement harvesting under various conditions.

Findings

Measurements can be performed without significantly disturbing entanglement harvesting.

Field measurements can sometimes enhance the amount of entanglement harvested.

Certain regimes allow measurement during entanglement preparation without major interference.

Abstract

We analyzed how entanglement harvesting is affected by the performance of a measurement on the quantum field. The measurement on the field is modelled as the coupling of a particle detector to the field, followed by a projective measurement performed on the detector. In our analysis, we considered different arrangements for two detectors harvesting entanglement and an ancillary detector used to perform a measurement. We found different regimes for how performing measurements on the field affects the entanglement harvested, depending on the initial and final states of the detector used to measure the field, as well as its coupling strength. We identified the regimes where it is possible to measure the field during the preparation of entanglement harvesting protocols without significantly interfering in the entanglement harvested. We also identify in what regimes the field measurement can degrade or slightly enhance the ability of particle detectors to harvest entanglement.