Eur. Phys. J. B 73, 215-221 (2010)
https://doi.org/10.1140/epjb/e2010-00005-x

Spin filtering effects in a one dimensional artificial lattice with ring geometry subject to Rashba coupling

¹ INFN, Laboratori Nazionali di Frascati, P.O. Box 13, 00044 Frascati, Italy
² Department of Physics “A. Volta”, University of Pavia, Via Bassi 6, 27100 Pavia, Italy

Corresponding author: stefano.bellucci@lnf.infn.it

Received: 20 April 2009
Revised: 11 September 2009
Published online: 15 January 2010

Abstract

Quantum interference effects in rings provide suitable means for controlling spin at mesoscopic scales. Here we apply such a control mechanism to the spin dependent transport in a one-dimensional Aharonov-Bohm (AB) ring patterned in two-dimensional electron gases (2DEGs) symmetrically coupled to two leads. We investigate the ballistic conductance in the presence of an artificial crystal, which is made up of 5 quantum dots. The study is essentially based on the natural spinorbit interactions, due to the quantum well potential that confines electrons in the 2DEG. We focus on single-channel transport and solve for the spin polarization of the current. As an important consequence of the presence of spin splitting, we find the occurrence of spin dependent current oscillations. The presence of lattice can be useful to improve the spin filtering capability of the QR. In fact modulating both the geometry of the dots and the strength of the tunnel barriers between them it is now possible to obtain well defined spin-dependent resonances allowing polarized transport. The presence of isolated conductance peak is useful in order to improve the efficiency of the spin filtering also at non zero temperatures.