Generation of electric current and electromotive force by an antiferromagnetic domain wall

Dynamic magnetic textures may transfer the angular moment from the varying in time antiferromagnetic order to spins of conduction electrons. Due to the spin orbit coupling (SOC) these spin excitations can induce the electric current of conduction electrons. We calculated the electric current and the electromotive force (EMF) which are produced by a domain wall (DW) moving parallel to the magnetically compensated interface between an antiferromagnetic insulator (AFMI) and a two-dimensional spin orbit coupled metal. Spins of conduction electrons interact with localized spins of a collinear AFMI through the interface exchange interaction. The Keldysh formalism of nonequilibrium Green functions was applied for the analysis of this system. It is shown that a Bloch DW generates the current perpendicular to the DW motion direction. At the same time a N\'{e}el DW creates the electric potential which builds up across the wall. The total charge which is pumped by a Bloch DW can be expressed in terms of a topologically invariant charge quantum. The latter does not depend on variations of DW's velocity and shape. These effects increase dramatically when the Fermi energy approaches the van Hove singularity of the Fermi surface. The obtained results are important for the electrical detection and control of dynamic magnetic textures in antiferromagnets.Comment: 11 pages, 2 figure

Generation of spin current and polarization under dynamic gate control of spin-orbit interaction in low-dimensional semiconductor systems

Based on the Keldysh formalism, the Boltzmann kinetic equation and the drift diffusion equation have been derived for studying spin polarization flow and spin accumulation under effect of the time dependent Rashba spin-orbit interaction in a semiconductor quantum well. The time dependent Rashba interaction is provided by time dependent electric gates of appropriate shapes. Several examples of spin manipulation by gates have been considered. Mechanisms and conditions for obtaining the stationary spin density and the induced rectified DC spin current are studied.Comment: 10 pages, 3 figures, RevTeX

Quantum oscillations of spin current through a III-V semiconductor loop

We have investigated the transport of spin polarization through a classically chaotic semiconductor loop with a strong Rashba spin-orbit interaction. We found that if the escape time of a particle is long enough, the configuration averaged spin conductance oscillates strongly with the geometric spin phase. We predict a sizable rotation of spin polarization along its flowing path across the loop from the injector to the collector. We have also discovered a quantized universal spin relaxation in a 2D reservoir connected to such a semiconductor loop.Comment: 4 pages, 1 figur