Spin-electric stripes: Electric voltage induced by spin currents

TL;DR

This paper predicts the formation of spin-polarized electric field stripes at the edges of a 2D conductor due to spin currents, with implications for spintronics and experimental detection.

Contribution

It introduces a novel theoretical model describing electric field stripes induced by spin currents in 2D conductors, including effects of spin relaxation.

Findings

Opposite spin polarization at boundaries with electric field stripes

Electric fields related to spin current magnitude and direction

Persistence of spin polarization at edges despite relaxation

Abstract

At each of the boundaries of the two-dimensional (2D) rectangular conductor parallel to the electric current there arises a stripe with an electric field transverse to the current and a 100% electron spin polarization. The two stripes have opposite spin orientations and opposite directions of electric fields. The magnitudes of the fields, directly related to the spin current if the spin relaxation is negligible, are the same. The periphery stripes are separated by a center-stripe, in which the magnitude and direction of the electric field depend on the ratio of the skew scattering and side jump spin currents. The spin polarization is zero on the center-line and reaches +1 or -1 at the boundaries between the central and periphery stripes. Weak relaxation of the z-component of spin normal to the 2D plane modifies the magnitudes of the spin polarization and fields, with +1 (-1) spin polarization persisting at the edges of the sample. Favorable experimental settings, in which the electron spin relaxation of the z-component of spin is suppressed but the spin current is not, are discussed.