Entanglement Amplification from Rotating Black Holes

TL;DR

This paper investigates how rotation in a BTZ black hole enhances the quantum vacuum entanglement harvesting between particle detectors, especially near-extremal small black holes, reducing the entanglement shadow.

Contribution

It demonstrates that black hole rotation can significantly amplify vacuum entanglement harvesting, revealing new effects of angular momentum on quantum correlations in curved spacetime.

Findings

Rotation amplifies entanglement harvesting by up to an order of magnitude.

Near-extremal small black holes show the strongest amplification effects.

The entanglement shadow shrinks with increasing black hole angular momentum.

Abstract

The quantum vacuum has long been known to be characterized by field correlations between spacetime points. These correlations can be swapped with a pair of particle detectors, modelled as simple two-level quantum systems (Unruh-DeWitt detectors) via a process known as entanglement harvesting. We study this phenomenon in the presence of a rotating BTZ black hole, and find that rotation can significantly amplify the harvested vacuum entanglement. Concurrence between co-rotating detectors is amplified by as much as an order of magnitude at intermediate distances from the black hole relative to that at large distances. The effect is most pronounced for near-extremal small mass black holes, and allows for harvesting at large spacelike detector separations. We also find that the entanglement shadow -- a region near the black hole from which entanglement cannot be extracted -- is diminished in size as the black hole's angular momentum increases.