In-plane Magnetic Field Dependent Magnetoresistance of Gated Asymmetric Double Quantum Wells

TL;DR

This study explores how in-plane magnetic fields and gating influence the magnetoresistance in asymmetric double quantum wells, revealing tunable electron properties through structural and electrical modifications.

Contribution

It provides experimental insights into controlling electron occupancy and tunneling in asymmetric double quantum wells via magnetic fields and gating.

Findings

Magnetoresistance varies with in-plane magnetic field and gate voltage.

Electron occupancy in wells can be tuned by barrier parameters and gating.

Tunneling between wells affects magnetoresistance behavior.

Abstract

We have investigated experimentally the magnetoresistance of strongly asymmetric double-wells. The structures were prepared by inserting a thin Al$_{0.3}$Ga$_{0.7}$As barrier into the GaAs buffer layer of a standard modulation-doped GaAs/Al$_{0.3}$Ga$_{0.7}$As heterostructure. The resulting double-well system consists of a nearly rectangular well and of a triangular well coupled by tunneling through the thin barrier. With a proper choice of the barrier parameters one can control the occupancy of the two wells and of the two lowest (bonding and antibonding) subbands. The electron properties can be further influenced by applying front- or back-gate voltage.