Holographic confining/deconfining gauge theories and entanglement measures with a magnetic field

TL;DR

This paper investigates how a background magnetic field influences various holographic entanglement measures in confining and deconfined phases, revealing anisotropic effects and phase transition behaviors in the entanglement structure.

Contribution

It provides a detailed analysis of magnetic field effects on multiple entanglement measures within a holographic QCD model, highlighting anisotropic and phase transition phenomena.

Findings

Magnetic field causes anisotropic behavior in entanglement measures.

Phase transitions in entanglement entropy and negativity depend on magnetic field orientation.

Entanglement wedge always exceeds half of the mutual information across phases.

Abstract

We study various holographic pure and mixed state entanglement measures in the confined/deconfined phases of a bottom-up AdS/QCD model in the presence of a background magnetic field. We analyse the entanglement entropy, entanglement wedge cross-section, mutual information, and entanglement negativity and investigate how a background magnetic field leaves its imprints on the entanglement structure of these measures. Due to the anisotropy introduced by the magnetic field, we find that the behaviour of these measures depends nontrivially on the relative orientation of the strip with respect to the field. In the confining phase, the entanglement entropy and negativity undergo a phase transition at the same critical strip length, the magnitude of which increases/decreases for parallel/perpendicular orientation of the magnetic field. The entanglement wedge cross-section similarly displays discontinuous behaviour each time a phase transition between different entangling surfaces occurs, while further exhibiting anisotropic features with a magnetic field. We further find that the magnetic field also introduces substantial changes in the entanglement measures of the deconfined phase, however, these changes remain qualitatively similar for all orientations of the magnetic field. We further study the inequality involving entanglement wedge and mutual information and find that the former always exceeds half of the latter everywhere in the parameter space of the confined/deconfined phases.