Magnetoresistance calculations for a two-dimensional electron gas with unilateral short-period strong modulation

TL;DR

This paper develops a quantum-mechanical model to accurately calculate magnetoresistance oscillations in strongly modulated two-dimensional electron gases, surpassing semiclassical methods and aligning well with experimental data.

Contribution

It introduces a tight-binding quantum model combined with Kubo's formula for magnetoresistance, providing better insights into strong magnetic field effects in superlattices.

Findings

Model matches experimental magnetoresistance data

Quantum approach outperforms semiclassical descriptions at high fields

Provides intuitive understanding of magnetic breakdown effects

Abstract

The linear response theory is used to describe magnetoresistance oscillations of short-period unilateral superlattices with strong modulation (or alternatively arrays of coupled quantum wires). The semiclassical description of this system fails for strong magnetic fields (magnetic breakdown) and we employ a simple fully-quantum-mechanical tight-binding model in conjunction with Kubo's formula instead. The resulting magnetoresistance data nicely compare to the experiments while the model opens good intuitive insight into the effects taking place in the system.