Electron magnetotransport in GaAs/AlGaAs superlattices with weak and strong inter-well coupling

TL;DR

This study investigates how illumination affects electron transport in GaAs/AlGaAs superlattices, revealing a transition from 3D to 2D behavior and changes in tunneling properties.

Contribution

It demonstrates that illumination can induce a dimensionality transition and modify tunneling in superlattices, supported by experimental data and tight-binding calculations.

Findings

Illumination reduces electron tunneling in superlattices.

Transition from 3D to 2D electron behavior upon illumination.

Enhanced electron concentration after illumination.

Abstract

We report on magnetotransport measurements in two MBE-grown GaAs/AlGaAs superlattices formed by wide and narrow quantum wells and thin Si-doped barriers subject to tilted magnetic fields. It has been shown that illumination of the strongly coupled superlattice with narrow wells leads to reduction of its dimensionality from the 3D to 2D. The illumination-induced transition is revealed by remarkable change of magnetoresistance curves as compared to those measured before illumination. The experimental data along with tight-binding model calculations indicate that the illumination not only enhances the electron concentration but also suppresses the electron tunneling through the barriers.