Bipolar Spin Switch Using Aharonov–Bohm Ring With Embedded Double Quantum Dots

Author

Chen, Kuo-Wei ; Liu, Ming-Hao ; Chen, Son-Hsien ; Chang, Ching-Ray

Author_Institution

Dept. of Phys., Nat. Taiwan Univ., Taipei

Volume

43

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

2866

Lastpage

2868

Abstract

We report on the analysis of quantum transport through an Aharonov-Bohm ring with embedded double quantum dots. The normal metal leads are assumed to be weakly coupled to the two quantum dots. In the quantum dot region, Rashba spin-orbit coupling and electron-electron interaction are considered. The quantum transport is analyzed based on the Keldysh nonequilibrium Green´s function formalism. A spin-polarized current emerges in this device due to the combined effect of a magnetic flux, threading through the AB ring, and the Rashba spin-orbit coupling. An interesting switching property of the spin polarization by turning on and off the gate within small voltage window is observed. This feature, however, does not exist in the Aharonov-Bohm ring structure with single quantum dot. We therefore propose a theoretical idea of a bipolar spin polarization switch

Keywords

Aharonov-Bohm effect; bipolar transistor switches; exchange interactions (electron); quantum dots; spin polarised transport; spin-orbit interactions; Aharonov-Bohm ring; Keldysh nonequilibrium Green´s function; bipolar spin switch; electron-electron interaction; embedded double quantum dots; quantum transport; spin polarization; spin-polarized current; Charge carrier processes; Couplings; Green´s function methods; Lead; Magnetic analysis; Magnetic flux; Polarization; Quantum dots; Switches; Turning; Aharonov–Bohm ring; Keldysh nonequilibrium formalism; Rashba spin-orbit coupling; quantum dot;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2007.893300

Filename

4202818