  We observe nearly vanishing Hall resistances for integer filling factors in a
counterflow (CF) experiment on a density balanced 2D bilayer system. Filling
factor dependent equilibration lengths demonstrate enhanced 1D coupling via
edge-channels. Due to the narrow barrier the edge-modes of the two 2DEGs are in
close proximity allowing for 1D excitonic correlations. Electron drag
measurements confirm the observed quantum state selective coupling between the
layers.
