Holographic entanglement entropy for $Lif_4^{(2)}\times {S}^1\times S^5$ spacetime with string excitations

TL;DR

This paper investigates holographic entanglement entropy in a Lifshitz spacetime with string excitations, revealing that the entropy density of excitations remains size-independent at first order, and discusses implications for entanglement thermodynamics.

Contribution

It provides an exact analysis of entanglement entropy in a Lifshitz background with string excitations, highlighting size-independent entropy density and its thermodynamic interpretation.

Findings

Net entropy density is independent of subsystem size.

Flow to a different Lifshitz vacuum in IR due to excitations.

Results support a first law-like relation in entanglement thermodynamics.

Abstract

The (F1,D2,D8) brane configuration with $Lif_4^{(2)}\times {S}^1\times S^5$ geometry is a known Lifshitz vacua supported by massive $B_{\mu\nu}$ field in type IIA theory. This system allows exact IR excitations which couple to massless modes of the fundamental string. Due to these massless modes the solutions have a flow to a dilatonic $Lif_4^{(3)}\times S^1\times S^5$ vacua in IR. We study the entanglement entropy on the boundary of this spacetime for the strip and the disc subsystems. To our surprise net entropy density of the excitations at first order is found to be independent of the typical size of subsystems. We interpret our results in the light of first law of entanglement thermodynamics.