Interlayer charge transfer in double-quantum-well systems

As the front-layer density in a bilayer electron or hole system is depleted by the application of a biased front gate, the density in the back layer increases due to the exchange term in the energy. For the sample parameters we studied, a self-consistent calculation using the local-density approximation predicts a discontinuous charge transfer that is not observed experimentally. We discuss possible origins of this discrepancy.