Soliton Stars as Holographic Confined Fermi Liquids

TL;DR

This paper explores a holographic model of confined Fermi liquids using charged fermion fluids in AdS soliton geometry, revealing phase structures, stability conditions, and multiple Fermi surfaces, with implications for confinement/deconfinement transitions.

Contribution

It introduces a novel holographic confined Fermi liquid model called soliton star, analyzing its phase structure, stability, and Fermi surface properties, extending the electron star concept.

Findings

Identified three phase structures depending on fermion parameters.

Found a stable soliton star solution that approaches the electron star.

Indications of a decay from soliton star to inhomogeneous solutions.

Abstract

In this paper, we study a holographic dual of a confined fermi liquid state by putting a charged fluid of fermions in the AdS soliton geometry. This can be regarded as a confined analogue of electron stars. Depending on the parameters such as the mass and charge of the bulk fermion field, we found three different phase structures when we change the values of total charge density at zero temperature. In one of the three cases, our confined solution (called soliton star) is always stable and this solution approaches to the electron star away from the tip. In both the second and third case, we find a confinement/deconfinement phase transition. Moreover, in the third one, there is a strong indication that the soliton star decays into an inhomogeneous solution. We also analyze the probe fermion equations (in the WKB approximation) in the background of this soliton star geometry to confirm the presence of many fermi-surfaces in the system.