https://doi.org/10.1140/epjb/e2010-10767-6
Conductance oscillations of a spin-orbit stripe with polarized contacts
1
Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca, Spain
2
Institut de Física Interdisciplinària i de Sistemes Complexos
IFISC (CSIC-UIB), 07122 Palma de Mallorca, Spain
Corresponding author: a llorens.serra@uib.es
Received:
8
October
2010
Revised:
7
December
2010
Published online:
14
January
2011
We investigate the linear conductance of a stripe of spin-orbit interaction
in a 2D electron gas; that is, a
2D region of length 
along the
transport direction and infinite in the transverse one in which a spin-orbit
interaction of Rashba type is present.
Polarization in the contacts
is described by means of Zeeman fields.
Our model predicts two types of conductance oscillations:
Ramsauer oscillations in the minority spin transmission, when both
spins can propagate, and Fano oscillations when only one
spin propagates.
The latter are due to the spin-orbit coupling with quasibound
states of the non propagating spin.
In the case of polarized contacts in antiparallel configuration Fano-like oscillations
of the conductance
are still made possible by the spin orbit coupling, even though no spin component
is bound by the contacts.
To describe these behaviors we propose a
simplified model based on an ansatz wave function.
In general, we find that the contribution for vanishing transverse momentum dominates
and defines the conductance oscillations.
Regarding the oscillations with Rashba coupling intensity, our model confirms the
spin transistor behavior, but only for high degrees of polarization.
Including a position dependent effective mass yields additional
oscillations due to the mass jumps at the interfaces.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2011
