Spin injection and electric field effect in degenerate semiconductors

TL;DR

This paper investigates spin transport in degenerate semiconductors, emphasizing the effects of electric fields, carrier interactions, and density variations, revealing unique behaviors distinct from metallic regimes.

Contribution

It introduces a comprehensive drift-diffusion model including many-body effects to analyze spin injection in degenerate semiconductors, highlighting their unique transport properties.

Findings

Carrier-carrier interactions significantly influence spin injection.

Electric fields modify spin transport characteristics.

Degenerate semiconductors exhibit distinct spin-transport regimes from metals.

Abstract

We analyze spin-transport in semiconductors in the regime characterized by $T\stackrel{<}{\sim}T_F$ (intermediate to degenerate), where $T_F$ is the Fermi temperature. Such a regime is of great importance since it includes the lightly doped semiconductor structures used in most experiments; we demonstrate that, at the same time, it corresponds to the regime in which carrier-carrier interactions assume a relevant role. Starting from a general formulation of the drift-diffusion equations, which includes many-body correlation effects, we perform detailed calculations of the spin injection characteristics of various heterostructures, and analyze the combined effects of carrier density variation, applied electric field and Coulomb interaction. We show the existence of a degenerate regime, peculiar to semiconductors, which strongly differs, as spin-transport is concerned, from the degenerate regime of metals.