Quantum hall effect in a quantum-well-wire superlattice GaAs/AlAs(311)A

摘要

High-magnetic field transport is studied in the series of quantum-well-wire structures AlAs/GaAs/AlAs obtained by the multilayered MBE growth on the gaAs(311)A surface. For the average gaAs layer thicknesses higher than 1.8 nm considerable difference is fund at low temperatures in zero-field conductances parallel and perpendicular to the wires while the corresponding low-temperature high-field dependencies of the Hall resistance are quaite similar. Several planteaus of the quatum Hall effect are observed concomitant with the magnetoresistance minima. The planteau at highest fields is within several percent at 25kOhm indicating the filling factor v chemical bounds 1 for the two-dimensional conductivity. But the next distinct plateau is around v chemical bounds 2.5 that imply some parallel conductivity, probably of one-dimensional nature.