A general holographic insulator/superconductor model away from the probe limit

Abstract: We investigate holographic phase transitions affected by dark matter sector in the AdS soliton background away from the probe limit. When neglecting backreaction, the scalar charge q can be scaled unity without loss of generality. While considering backreaction in this work, we obtain much more richer physics by choosing various scalar charge q. Firstly, we observe unstable retrograde condensation appears due to the dark matter sector and also derive stable conditions. For stable solutions, we find that the larger coupling parameter $\alpha$ makes the gap of condensation shallower and the critical chemical potential keeps as a constant with a large scalar charge q, which is similar to cases in the probe limit. In contrast, the dark matter sector could affect the critical chemical potential and the order of phase transitions for very small charge q. We also arrive at the same conclusion from the holographic topological entanglement entropy approach. Moreover, we state that the entanglement entropy approach is especially powerful in studying the effects of the dark matter sector in this general insulator/superconductor system.