Proposal for all-electrical measurement of T_1 in semiconductors

TL;DR

This paper proposes an all-electrical method to measure the spin relaxation time T_1 in magnetic semiconductors using the spin-voltaic effect in a magnetic p-n junction, enabling extraction of T_1, g-factor, and spin polarization.

Contribution

It introduces a novel electrical measurement technique for T_1 in magnetic semiconductors based on the spin-voltaic effect in magnetic p-n junctions.

Findings

T_1 can be determined from I-V characteristics.

Analytical expressions relate measurements to T_1, g-factor, and spin polarization.

Method enables all-electrical, non-optical spin relaxation measurements.

Abstract

In an inhomogeneously doped magnetic semiconductor spin relaxation time T_1 can be determined by all-electrical measurements. Nonequilibrium spin injected in a magnetic p-n junction gives rise to the spin-voltaic effect where the nonequilibrium spin-induced charge current is very sensitive to T_1 and can flow even at no applied bias. It is proposed that T_1 can be determined by measuring the I-V characteristics in such a geometry. For a magnetic p-n junction where the results can be calculated analytically, it is in addition possible to extract the g-factor and the degree of injected carrier spin polarization.