Bose-Einstein condensation and superfluidity of magnetoexcitons in bilayer graphene

We propose experiments to observe Bose-Einstein condensation and superfluidity of quasi-two-dimensional spatially indirect magnetoexcitons in two-layer graphene. The energy spectrum of collective excitations, the sound spectrum, and the effective magnetic mass of magnetoexcitons are presented in the strong magnetic field regime. The superfluid density nS and the temperature of the Kosterlitz-Thouless phase transition Tc are shown to be increasing functions of the excitonic density n but decreasing functions of B and the interlayer separation D