Probing Spin-Polarized Currents in the Quantum Hall Regime

TL;DR

This paper proposes an experiment to detect spin-polarized currents in the quantum Hall regime using ZnMnSe contacts and predicts a doubled Hall resistance at full spin injection, with implications for understanding spin transport.

Contribution

It introduces a novel experimental setup combining ZnMnSe contacts with a GaAs 2DEG to probe spin-polarized currents and provides theoretical predictions for Hall resistance changes.

Findings

Hall resistance doubles at 100% spin injection for filling factor ν=2

Spin equilibration affects Hall resistance measurements

No coupling expected at odd filling factors with full spin injection

Abstract

An experiment to probe spin-polarized currents in the quantum Hall regime is suggested that takes advantage of the large Zeeman-splitting in the paramagnetic diluted magnetic semiconductor zinc manganese selenide (Zn$_{1-x}$Mn$_x$Se). In the proposed experiment spin-polarized electrons are injected by ZnMnSe-contacts into a gallium arsenide (GaAs) two-dimensional electron gas (2DEG) arranged in a Hall bar geometry. We calculated the resulting Hall resistance for this experimental setup within the framework of the Landauer-B\"uttiker formalism. These calculations predict for 100% spininjection through the ZnMnSe-contacts a Hall resistance twice as high as in the case of no spin-polarized injection of charge carriers into a 2DEG for filling factor $\nu=2$. We also investigated the influence of the equilibration of the spin-polarized electrons within the 2DEG on the Hall resistance. In addition, in our model we expect no coupling between the contact and the 2DEG for odd filling factors of the 2DEG for 100% spininjection, because of the opposite sign of the g-factors of ZnMnSe and GaAs.