22,756 research outputs found
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
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
Bethe-Salpeter study of radially excited vector quarkonia
We solve the Bethe-Salpeter equation (BSE) for a system of a heavy
quark-antiquark pair interacting with a Poincare invariant generalization of
screened linear confining potential. In order to get reliable description the
Lorentz scalar confining interaction is complemented by the effective one gluon
exchange. Within presented model we reasonably reproduce all known radial
excitations of the vector charmonia. We have found that is the only
charmonium left bellow naive quark-antiquark threshold , while the all
excited states are situated above this threshold. We develop a method which is
enable to provide solution of full four dimensional BSE for the all excited
states. We discuss the consequences of the use of the free propagators for
calculation of excited states above the threshold. The Bethe-Salpeter string
breaking scale appears to be relatively larger then the one
defined in various potential models .Comment: typos and grammar correcte
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