Thermally-induced spin polarization of a two dimensional electron gas

TL;DR

This paper theoretically investigates how a temperature gradient induces in-plane spin polarization in a 2D electron gas with Rashba spin-orbit interaction, revealing sign changes at certain Fermi levels and comparing with electric field effects.

Contribution

It introduces a theoretical model showing thermally-induced spin polarization in 2D electron gases with Rashba interaction, highlighting the sign change at subband edges.

Findings

Temperature gradient causes in-plane spin polarization normal to the gradient.

Spin polarization changes sign when the Fermi level crosses the subband edge.

Comparison shows differences between thermal and electric field-induced spin polarization.

Abstract

Spin polarization of a two-dimensional electron gas with Rashba spin-orbit interaction, induced by a thermo-current, is considered theoretically. It is shown that a temperature gradient gives rise to an in-plane spin polarization of the electron gas, which is normal to the temperature gradient. The low-temperature spin polarization changes sign when the Fermi level crosses bottom edge of the upper electronic subband. We also compare the results with spin polarization induced by an external electric field (current).