Momentum conservation in tunneling processes between barrier-separated 2D-electron-gas systems

Abstract
We directly determine the momentum conservation rules for tunneling processes between two independently contacted two-dimensional-electron-gas systems on GaAs-GaAlAs heterostructures. In transverse magnetic fields, the conservation of the canonical momentum results in a new and giant broadening of the subband resonances. As a consequence, the mean values of the wave functions, even for nonoccupied subbands, can be determined directly.