Enhanced spin injection efficiency in a four-terminal quantum dots system

Ling Qin; Hai-Feng Lü; Yong Guo
February 2010
Applied Physics Letters;2/15/2010, Vol. 96 Issue 7, p072109
Academic Journal
Within the scheme of quantum rate equations, we investigate the spin-resolved transport through a double quantum dot system with four ferromagnetic terminals. We find that the injection efficiency of spin-polarized electrons can be significantly improved. When the magnetization in one of four ferromagnetic terminals is antiparallel with the other three, the current polarization rate through one dot can be greatly enhanced, accompanied by the drastic decrease through the other one. The mechanism is the exchange interaction between electrons in the two dots, which can be a promising candidate for the improvement of the spin injection efficiency.


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