A Laterally Modulated 2D Electron System in the Extreme Quantum Limit

TL;DR

This study investigates a 2D electron system with a surface superlattice, revealing complex magnetotransport behavior in the quantum limit, explained by the interplay of disorder and periodic potential modulation.

Contribution

It demonstrates how a surface superlattice influences magnetotransport in a 2DES under strong disorder, providing a theoretical framework for observed fluctuations.

Findings

Rich pattern of resistivity fluctuations at low Landau levels

Qualitative agreement between experimental data and theoretical models

Disorder dominates over periodic modulation in the observed phenomena

Abstract

We report on magnetotransport of a two-dimensional electron system (2DES), located 32 nm below the surface, with a surface superlattice gate structure of periodicity 39 nm imposing a periodic modulation of its potential. For low Landau level fillings $\nu$, the diagonal resistivity displays a rich pattern of fluctuations, even though the disorder dominates over the periodic modulation. Theoretical arguments based on the combined effects of the long-wavelength, strong disorder and the short-wavelength, weak periodic modulation present in the 2DES qualitatively explain the data.