VERTICAL TRANSPORT IN SEMICONDUCTOR SUPERLATTICES PROBED BY MINIBAND-TO-ACCEPTOR MAGNETOLUMINESCENCE

The cyclotron motion of electrons in coupled-well AlGaAs/GaAs superlattices is investigated by photoluminescence of conduction band to acceptor transitions in magnetic fields up to 13 T, applied either parallel or perpendicular to the layers. For parallel fields, three different regimes are observed as the ratio of the cyclotron radius to the superlattice period is reduced, namely, tunneling cyclotron motion within the miniband, miniband breakdown, and finally a transition from electric to magnetic quantization. A fully quantum-mechanical calculation agrees well with experiment. © 1990 The American Physical Society.