Phase Separation and Exotic Vortex Phases in a Two-Species Holographic Superfluid

At a finite temperature, the stable equilibrium states of a coupled two-component superfluid with the same mass in both non-rotating and rotating cases can be obtained by studying its real time dynamics via holography, the equilibrium state is the final stable state that does not change in time anymore in the evolution process . Without rotation, the spatial phase separated states of the two components become more stable than the miscible condensates state when the direct repulsive inter-component coupling constant $\eta>\eta_c=0.05$ when the Josephson coupling $\epsilon$ is turned off. While a finite $\epsilon$ will always prevent the two species to be separated spatially. Under rotation, with vanishing $\epsilon$, the quantum fluid reveals many equilibrium structures of vortex states by varying the $\eta$ from negative to positive, the interlaced vortex lattices undergo a phase transition to vortex sheets with each component made up of chains of single quantized vortices.