Illumination-induced changes of the Fermi surface topology in three-dimensional superlattices

TL;DR

This study investigates how brief illumination alters the Fermi surface topology in GaAs/AlGaAs superlattices, revealing significant changes in electronic properties and interlayer coupling through magnetoresistance measurements.

Contribution

It demonstrates that illumination can modify the Fermi surface topology and interlayer coupling in superlattices, providing new insights into light-induced electronic property control.

Findings

Illumination increases electron concentration and mobility.

It reduces coupling among 2D electron layers.

Magnetoresistance curves show topology changes.

Abstract

The magnetoresistance of the MBE-grown GaAs/AlGaAs superlattice with Si-doped barriers has been measured in tilted magnetic fields in the as-grown state, and after brief illumination by a red-light diode at low temperature, T is approximately 0.3 K. A remarkable illumination-induced modification of magnetoresistance curves has been observed, which indicates a significant change of the superlattice Fermi surface topology. Analysis of magnetoresistance data in terms of the tight-binding model reveals that not only electron concentration and mobility have been increased by illumination, but also the coupling among 2D electron layers in neighboring quantum wells has been reduced.