Vortex lattice states of TMDC bilayer exciton condensates in strong magnetic fields

Exciton condensates in 2D electron systems in strong magnetic fields have been studied extensively in recent years. Frequently used platforms include graphene or transition metal dichalcogenide (TMDC) bilayers. In these systems the electron and hole densities in each layer can be adjusted by tuning gate voltages. In this talk, we show that at strong magnetic fields the ground state of weakly unbalanced electron hole fluids is a bipartite lattice state with charged vortices and antivortices on opposite sublattices. The charges of vortices and antivortices can have either sign, are unequal in magnitude in general, and dependent on the relative difference between electron and hole densities. We will explain the relationship between these charged vortex excitations and the half-charged merons of the more commonly studied conduction band bilayer exciton condensates.[1,2]