Spin-polarized transport in a lateral two-dimensional diluted magnetic semiconductor electron gas

TL;DR

This paper theoretically investigates how a spatially periodic magnetic field influences spin-dependent transport in a 2D diluted magnetic semiconductor, revealing a robust mechanism for spin-polarized currents even with minimal overall spin polarization.

Contribution

It demonstrates that spin-dependent Fermi velocities can generate strong spin-polarized currents, independent of large spin polarization or impurity effects.

Findings

Electron Fermi velocity is highly spin-dependent under periodic magnetic fields.

Strong spin-polarized current can be achieved with negligible overall spin polarization.

Spin polarization of current is robust against impurity scattering.

Abstract

The transport property of a lateral two-dimensional diluted magnetic semiconductor electron gas under a spatially periodic magnetic field is investigated theoretically. We find that the electron Fermi velocity along the modulation direction is highly spin-dependent even if the spin polarization of the carrier population is negligibly small. It turns out that this spin-polarized Fermi velocity alone can lead to a strong spin polarization of the current, which is still robust against the energy broadening effect induced by the impurity scattering.