Theory of spin injection

TL;DR

This paper reviews the diffusive theory of spin injection, introduces new results for dc and ac regimes using the gamma-technique, and discusses enhancing spin injection with resistive contacts and analyzing junction parameters from ac data.

Contribution

It presents a simplified gamma-technique for calculating spin injection coefficients and explores the effects of resistive and non-conserving contacts on spin injection efficiency.

Findings

New results for dc and ac spin injection regimes

Resistive spin-selective contacts can enhance spin injection

Method to determine junction parameters from ac data

Abstract

Diffusive theory of spin injection is reviewed and a number of new results is presented for the dc and ac regimes. They were derived by means of the "gamma-technique" allowing to simplify the calculations by choosing the spin injection coefficients through different interfaces as the basic variables. The prospects for increasing spin injection by using resistive spin-selective contacts are emphasized and spin non-conserving contacts are introduced. Finding the basic parameters of a junction from the ac data is discussed.