Soliton Stars as Holographic Confined Fermi Liquids

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.