Experimental conditions for observation of electron-hole superfluidity in GaAs heterostructures.

The experimental parameter ranges needed to generate superfluidity in optical and drag experiments in GaAs double quantum wells are determined, using a formalism that includes self-consistent screening of the Coulomb pairing interaction in the presence of the superfluid. The very different electron and hole masses in GaAs make this a particularly interesting system for superfluidity, with exotic superfluid phases predicted in the BCS-BEC crossover regime. We find that the density and temperature ranges for superfluidity cover the range for which optical experiments have observed indications of superfluidity, but that existing drag experiments lie outside the superfluid range. However we also show that for samples with low mobility with no macroscopically connected superfluidity, if the superfluidity survived in randomly distributed localized pockets, standard quantum capacitance measurements could detect these pockets.