# Entanglement extracted from vacuum into accelerated Unruh-DeWitt detectors and energy conservation

## TL;DR

This paper investigates how entanglement can be extracted from the Minkowski vacuum using uniformly accelerated Unruh-DeWitt detectors, revealing conditions under which entanglement occurs and discussing energy conservation implications.

## Contribution

It provides a detailed analysis of entanglement extraction conditions for accelerated detectors in different configurations, highlighting the role of energy ratios and orientation.

## Key findings

- Entanglement is extracted when detectors are anti-parallelly accelerated with matching energy ratios.
- No entanglement occurs when detectors are accelerated parallelly or in different orientations.
- Energy conservation considerations relate to the entanglement extraction process.

## Abstract

We consider a pair of two-level Unruh-DeWitt detectors accelerated uniformly in the Minkowski vacuum of a massless neutral scalar field, and analyze, within the perturbation theory, the entanglement extracted from the vacuum into the Unruh-DeWitt detectors when the switching of the detectors are performed adiabatically enough at the asymptotic past and future. We consider the cases where the detectors are accelerated parallelly, anti-parallelly, and in differently orientated directions. We show that entanglement is extracted if they are accelerated anti-parallelly and the ratios of the excitation energy to the magnitude of the acceleration coincide between the two detectors. On the other hand, we find the detectors are not entangled when the detectors are accelerated parallelly or in orientated directions. We discuss these results from the viewpoint of the energy conservation associated with the timelike boost Killing vector fields tangent to the worldlines of the detectors.