Open Access Nano Ideas

Double Rashba Quantum Dots Ring as a Spin Filter

Feng Chi*, Xiqiu Yuan and Jun Zheng

Author Affiliations

Department of Physics, Bohai University, Jinzhou, 121000, People’s Republic of China

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Nanoscale Research Letters 2008, 3:343-347  doi:10.1007/s11671-008-9163-z

Published: 3 September 2008


We theoretically propose a double quantum dots (QDs) ring to filter the electron spin that works due to the Rashba spin–orbit interaction (RSOI) existing inside the QDs, the spin-dependent inter-dot tunneling coupling and the magnetic flux penetrating through the ring. By varying the RSOI-induced phase factor, the magnetic flux and the strength of the spin-dependent inter-dot tunneling coupling, which arises from a constant magnetic field applied on the tunneling junction between the QDs, a 100% spin-polarized conductance can be obtained. We show that both the spin orientations and the magnitude of it can be controlled by adjusting the above-mentioned parameters. The spin filtering effect is robust even in the presence of strong intra-dot Coulomb interactions and arbitrary dot-lead coupling configurations.

Quantum dots; Spin filter; Rashba spin–orbit interaction; Spin-dependent inter-dot coupling