Giant transverse magnetoresistance in an asymmetric system of three GaAs/AlGaAs quantum wells in a strong magnetic field at room temperature

TL;DR

This study reports a giant transverse magnetoresistance in asymmetric GaAs/AlGaAs quantum wells at room temperature, with resistance increasing significantly under high magnetic fields due to electron wave function rearrangement.

Contribution

First observation of giant transverse magnetoresistance in asymmetric quantum wells at room temperature, linked to electron wave function changes under magnetic field.

Findings

Resistance increases by a factor of 1.85 at 75 kOe

Magnetoresistance shows quadratic dependence at low fields

Tends to saturation at high magnetic fields

Abstract

The giant transverse magnetoresistance is observed in the case of photoinduced nonequilibrium carriers in an asymmetric undoped system of three GaAs/AlGaAs quantum wells at room temperature. In a magnetic field of 75 kOe, the resistance of 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. This phenomenon is attributed to the rearrangement of the electron wave function in magnetic field. Using the fact that the incoherent part of the scattering probability for electron scattering on impurities and bulk defects is proportional to the integral of the forth power of the envelope wave function, the calculated field dependence of the magnetoresistance is shown to be similar to that observed experimentally.