Is entanglement a probe of confinement?

TL;DR

This study investigates whether entanglement measures can serve as indicators of confinement in strongly coupled gauge theories, finding they are insensitive to confinement but respond to the presence of a mass scale.

Contribution

It demonstrates that entanglement measures do not distinguish confining from non-confining theories with a mass gap, challenging their use as confinement probes.

Findings

Entanglement measures cannot differentiate confining from non-confining theories with a mass gap.

Entanglement entropy phase transition is driven by a scale, not confinement.

Holographic entanglement quantities match conformal values near fixed points.

Abstract

We study various entanglement measures in a one-parameter family of three-dimensional, strongly coupled Yang-Mills-Chern-Simons field theories by means of their dual supergravity descriptions. A generic field theory in this family possesses a mass gap but does not have a linear quark-antiquark potential. For the two limiting values of the parameter, the theories flow either to a fixed point or to a confining vacuum in the infrared. We show that entanglement measures are unable to discriminate confining theories from non-confining ones with a mass gap. This lends support on the idea that the phase transition of entanglement entropy at large-N can be caused just by the presence of a sizable scale in a theory and just by itself should not be taken as a signal of confinement. We also examine flows passing close to a fixed point at intermediate energy scales and find that the holographic entanglement entropy, the mutual information, and the F-functions for strips and disks quantitatively match the conformal values for a range of energies.