Commensurability resonances in two-dimensional magneto-electric lateral superlattices

TL;DR

This study investigates classical magnetoresistance resonances in two-dimensional electron gases within hybrid superlattices, revealing quasi-commensurate snake trajectories and their effects on transport properties, supported by experimental and numerical analysis.

Contribution

It demonstrates the existence of commensurability resonances in magneto-electric superlattices and provides a combined experimental and semiclassical simulation approach to understand these phenomena.

Findings

Pronounced classical resonances in magnetoresistivity perpendicular to magnetic modulation.

Sharp increase in magnetoresistivity along the magnetic modulation above a threshold field.

Resonances linked to snake trajectories quasi-commensurate with antidot lattice.

Abstract

Hybrid lateral superlattices composed of a square array of antidots and a periodic one-dimensional magnetic modulation are prepared in $\mathrm{Ga[Al]As}$ heterostructures. The two-dimensional electron gases exposed to these superlattices are characterized by magnetotransport experiments in vanishing average perpendicular magnetic fields. Despite the absence of closed orbits, the diagonal magnetoresistivity in the direction perpendicular to the magnetic modulation shows pronounced classical resonances. They are located at magnetic fields where snake trajectories exist which are quasi-commensurate with the antidot lattice. The diagonal magnetoresistivity in the direction of the magnetic modulation increases sharply above a threshold magnetic field and shows no fine structure. The experimental results are interpreted with the help of numerical simulations based on the semiclassical Kubo model.