Properties of gapped systems in AdS/BCFT

TL;DR

This paper investigates the properties of gapped holographic systems with boundaries in AdS/BCFT, focusing on conductivities and entanglement entropy behaviors in two models, revealing trivial boundary conductivities and distinct entanglement entropy patterns.

Contribution

It compares two holographic gapped systems in AdS/BCFT, analyzing their conductivities and entanglement entropy, highlighting differences in entanglement behavior and boundary effects.

Findings

Boundary conductivities are trivial in both models.

Entanglement entropy decreases monotonically in the Einstein-scalar system.

Entanglement entropy exhibits a discontinuous drop in the AdS soliton model.

Abstract

We study the conductivities and entanglement structures of two different holographic gapped systems at zero density in the presence of boundaries within AdS/BCFT. The first gapped system is described by the Einstein-scalar gravity and the second one is the dual of AdS soliton geometry. We show that in both these two systems the bulk and boundary conductivities along the spatial direction of the boundary of BCFT are trivial. For the first system, when we increase the size of the subsystem the renormalized entanglement entropy is always non-negative and monotonically decreasing with discontinuous, or continuous, or smooth behavior, depending on the effective tension of the brane. While for the AdS soliton with a boundary, the renormalized entanglement entropy only exhibits a discontinuous drop when we increase the size of the subsystem.