Parallel Magnetic Field Tuning of Valley Splitting in AlAs Two-Dimensional Electrons

TL;DR

This paper shows how a parallel magnetic field can tune valley energies in AlAs quantum wells, revealing enhanced valley susceptibility due to electron interactions, which could impact valleytronic applications.

Contribution

It introduces a method to control valley splitting in AlAs 2D electrons using parallel magnetic fields, highlighting interaction effects beyond non-interacting models.

Findings

Valley energies can be tuned by parallel magnetic fields.

Enhanced valley susceptibility indicates strong electron-electron interactions.

Experimental results differ from non-interacting theoretical predictions.

Abstract

We demonstrate that, in a quasi-two-dimensional electron system confined to an AlAs quantum well and occupying two conduction-band minima (valleys), a parallel magnetic field can couple to the electrons' orbital motion and tune the energies of the two valleys by different amounts. The measured density imbalance between the two valleys, which is a measure of the valley susceptibility with respect to parallel magnetic field, is enhanced compared to the predictions of non-interacting calculations, reflecting the role of electron-electron interaction.