Eur. Phys. J. B (2014) 87: 6
https://doi.org/10.1140/epjb/e2013-40963-7

Regular Article

Spin-filtering and charge- and spin-switching effects in a quantum wire with periodically attached stubs

¹ School of Computer, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, P.R. China
² School of Mechatronics & Engineering, East China Jiaotong University, Nanchang 330013, P.R. China
³ School of Basic Science, East China Jiaotong University, Nanchang 330013, P.R. China
⁴ Department of Physics and Key Laboratory for Low-Dimensional Quantum Structures and Manipulation (Ministry of Education), Hunan Normal University, Changsha 410081, P.R. China

^a e-mail: xxb_11@hotmail.com
^b e-mail: ghzhou@hunnu.edu.cn

Received: 15 December 2012
Received in final form: 21 January 2013
Published online: 7 January 2014

Abstract

Spin-dependent electron transport in a periodically stubbed quantum wire in the presence of Rashba spin-orbit interaction (SOI) is studied via the nonequilibrium Green’s function (GF) method combined with the Landauer-Büttiker formalism. By comparing with a straight Rashba quantum wire, the magnitude of spin conductance can be enhanced obviously. In addition, the charge and spin switching can also be found in the considered system. The mechanism of these transport properties is revealed by analyzing the total charge density and spin-polarized density distributions in the stubbed quantum wire. Furthermore, periodic spin-density islands with high polarization are also found inside the stubs, owing to the interaction between the charge density islands and the Rashba SOI-induced effective magnetic field. These interesting findings may be useful in further understanding of the transport properties of low-dimensional systems and in devising an all-electrical multifunctional spintronic device based on the proposed structure.