GIANT TRANSVERSE MAGNETORESISTANCE IN AN ASYMMETRIC SYSTEM OF 3 GAAS ALGAAS QUANTUM-WELLS IN STRONG MAGNETIC-FIELD AT ROOM-TEMPERATURE/

The giant transverse magnetoresistance is observed in the case of phot oinduced nonequilibrium carriers in an asymmetric undoped system of th ree GaAs/AlGaAs quantum wells at room temperature. In a magnetic field of 75 kOe, resistance of the nanostructure being studied increases by a factor of 1.85. The magnetoresistance depends quadratically on the magnetic field in low fields and tends to saturation in high fields. T his phenomenon is attributed to the rearrangement of the electron wave function in magnetic field. Using the fact that the incoherent part o f the scattering probability for electron scattering on impurities and bulk defects is proportional to the integral of the forth power of th e envelope wave function, the calculated field dependence of the magne toresistance is shown to be similar to that observed experimentally.