Investigations of the νT=1 exciton condensate

Recent experiments on quantum Hall bilayers in the vicinity of total filling factor 1 (νT=1) have revealed many exciting observations characteristic of a superfluidic exciton condensate. We report on our experimental work involving the νT=1 exciton condensate in independently contacted bilayer two-dimensional electron systems. We observe previously reported phenomena as a zero-bias resonant tunneling peak, a quantized Hall drag resistivity, and in counter-flow configuration, the near vanishing of both ρxx and ρxy resistivity components. At balanced electron densities in the layers, we find for both drag and counter-flow current configurations, thermally activated transport with a monotonic increase of the activation energy for d/ℓB