Holographic metals at finite volume

A bstract We construct the electron star solution in asymptotically global AdS spacetime, and investigate its thermodynamic stability properties, both globally with respect to the Reissner-Nordström and thermal AdS spacetimes, and under local perturbations of the thermodynamic variables. The solution is sourced with a perfect fluid at finite temperature, which implies that the “suspended electron cloud” previously reported in the literature does not appear as an equilibrium phase. We interpret the resulting system as that of a holographic metal confined to a finite volume. The corresponding grand canonical phase diagram reveals a rich structure of transitions involving three dominant phases, which depend strongly on the fluid parameters characterizing the star. Finally, we identify a quantum critical point at finite chemical potential, around which these different phases are organized.