62 research outputs found
Spin transmission through quantum dots with strong spin-orbit interaction
Quantum oscillations of the spin conductance through regular and chaotic 2D
quantum dots under the varying Rashba spin orbit interaction and at zero
magnetic field have been numerically calculated by summing up the spin
evolution matrices for classical transmitting trajectories. Fourier analysis of
these oscillations showed power spectra strongly dependent on the dot geometry.
For narrow rings the spectra are dominated by a single peak in accordance with
previous analytic results. In other geometries the spectra are represented by
multiple peaks for regular QD and quasicontinuum for chaotic QD.Comment: 10 pages, 5 figure
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
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