Ma, Jing-Min and Zhao, Jia and Zhang, Kai-Cheng and Peng, Ya-Jing and Chi, Feng (2011) Quantum interference effect in electron tunneling through a quantum-dot-ring spin valve. Nanoscale Research Letters, 6 (1). pp. 1-8.
Official URL: http://www.nanoscalereslett.com/content/6/1/265
Spin-dependent transport through a quantum-dot (QD) ring coupled to ferromagnetic leads with noncollinear magnetizations is studied theoretically. Tunneling current, current spin polarization and tunnel magnetoresistance (TMR) as functions of the bias voltage and the direct coupling strength between the two leads are analyzed by the nonequilibrium Green's function technique. It is shown that the magnitudes of these quantities are sensitive to the relative angle between the leads' magnetic moments and the quantum interference effect originated from the inter-lead coupling. We pay particular attention on the Coulomb blockade regime and find the relative current magnitudes of different magnetization angles can be reversed by tuning the inter-lead coupling strength, resulting in sign change of the TMR. For large enough inter-lead coupling strength, the current spin polarizations for parallel and antiparallel magnetic configurations will approach to unit and zero, respectively.
|Subjects:||Physical Science > Nanophysics|
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
|Divisions:||Faculty of Engineering, Science and Mathematics > School of Chemistry|
|Deposited On:||18 Oct 2011 08:20|
|Last Modified:||18 Oct 2011 08:20|
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