Entanglement harvesting: state dependence and covariance

TL;DR

This paper investigates how entanglement harvesting depends on initial states and field covariance, showing that under certain conditions, the harvested entanglement remains covariant up to second order in perturbation theory.

Contribution

It demonstrates that entanglement harvesting is covariant up to second order despite detector state dependence and spatial smearing effects.

Findings

Entanglement harvesting is covariant up to second order in perturbation theory.

Spatial smearing of detectors affects covariance but not the harvested entanglement at this order.

The analysis applies to arbitrary initial detector states and quasifree field states.

Abstract

We analyze entanglement harvesting for arbitrary initial states of particle detectors and arbitrary quasifree states of the field. Despite the fact that spatially smeared particle detectors are known to break covariance for arbitrary initial states, we show that the entanglement harvested by a pair of detectors from a quasifree state of a scalar field is a covariant quantity up to second order in perturbation theory.