Entanglement rules for holographic Fermi surfaces

TL;DR

This paper investigates how entanglement thermodynamics laws are modified in holographic quantum field theories with hyperscaling violation, revealing a new entanglement chemical potential linked to hidden Fermi surfaces.

Contribution

It introduces the concept of an entanglement chemical potential for theories with quark-like excitations, showing its independence from entangling region size and dependence on boundary quark degrees of freedom.

Findings

Modified first law of entanglement thermodynamics with an additional chemical potential term

Entanglement chemical potential is size-independent and determined by boundary quark degrees of freedom

Identification of entanglement chemical potential associated with hidden Fermi surfaces

Abstract

In this paper, based on the notion of Gauge/Gravity duality, we explore the laws of entanglement thermodynamics for most generic classes of Quantum Field Theories with hyperscaling violation. In our analysis, we note that for Quantum Field Theories with compressible \textit{quark} like excitation, the first law of entanglement thermodynamics gets modified due to the presence of an additional term that could be identified as the entanglement chemical potential associated with \textit{hidden} Fermi surfaces of the boundary theory. Most notably, we find that the so called entanglement chemical potential does not depend on the size of the entangling region and is purely determined by the quark d.o.f. encoded within the entangling region.