Enhancement of valley susceptibility upon complete spin-polarization

TL;DR

This study demonstrates that valley susceptibility in a 2D electron system increases when the system transitions from partial to full spin polarization, highlighting the interplay between spin and valley degrees of freedom.

Contribution

It provides new experimental evidence showing the enhancement of valley susceptibility upon full spin polarization in AlAs quantum wells.

Findings

Valley susceptibility increases with full spin polarization.

Spin susceptibility is higher in single-valley than in two-valley systems.

Experimental measurements confirm the coupling between spin and valley properties.

Abstract

Measurements on a two-dimensional electron system confined to an AlAs quantum well reveal that for a given electron density the valley susceptibility, defined as the change in valley population difference per unit strain, is enhanced as the system makes a transition from partial to full spin polarization. This observation is reminiscent of earlier studies in which the spin susceptibility of AlAs electrons was observed to be higher in a single-valley system than its two-valley counterpart.