Playing Pure Spin Current in Helimagnets: Toward Chiral Spin-Orbitronics

Abstract

A quantum theory of electron spin transport in conductive magnets is developed. The theory describes a large number of effects that arise due to spin-orbit scattering of conduction electrons on crystal lattice defects, such as the spin Hall effect, the inverse spin Hall effect, and the anomalous Hall effect. The transport through the contact of two different conductive magnetics is also considered; the phenomenological boundary conditions for the charge and spin flows are formulated, which make it possible to take into account the spin flip at the interface. The developed electron spin transport theory is used to describe the spin-orbitronics of the “helimagnet metal/non-magnetic metal” heterojunction. The spatial distribution of the polarization of the spin current injected into the helimagnet is found, and the characteristic decay lengths of different components of the polarization vector of the spin current are determined.