A pure spin-current injector of semiconductor quantum dots with Andreev reflection and Rashba spin-orbit coupling  

作　　者：叶成芝 聂一行 梁九卿 

机构地区：[1]Institute of Condensed Matter Physics and School of Sciences,Linyi University [2]Institute of Theoretical Physics and Department of Physics,Shanxi University

出　　处：《Chinese Physics B》2011年第12期350-356,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 10775091,10774094,10974124,and 11047172);the Excellent Youth and Midlife Scientist Scientific Research Encouragement Foundation of Shandong Province,China(Grant No. BS2010DS006);the Doctor Research Startup Foundation of Linyi University,China (Grant No. BS201023)

摘　　要：We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction （RSOI）, coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two ferromagnetic leads and two quantum dots form a ring threaded by Aharonov-Bohm （AB） flux. This device possesses normal quasiparticle transmission between the two ferromagnetic leads, and normal and crossed Andreev reflections providing conductive holes. For the appropriate spin polarization of the ferromagnetic leads, RSOI and AB flux, the pure spin-up （or spin-down） current without net charge current in the right lead, which is due to the equal numbers of electrons and holes with the same spin-polarization moving along the same direction, can be obtained by adjusting the gate voltage, which may be used in practice as a pure spin-current injector.We propose a four-terminal device consisting of two parallel quantum dots with Rashba spin-orbit interaction （RSOI）, coupled to two side superconductor leads and two common ferromagnetic leads, respectively. The two ferromagnetic leads and two quantum dots form a ring threaded by Aharonov-Bohm （AB） flux. This device possesses normal quasiparticle transmission between the two ferromagnetic leads, and normal and crossed Andreev reflections providing conductive holes. For the appropriate spin polarization of the ferromagnetic leads, RSOI and AB flux, the pure spin-up （or spin-down） current without net charge current in the right lead, which is due to the equal numbers of electrons and holes with the same spin-polarization moving along the same direction, can be obtained by adjusting the gate voltage, which may be used in practice as a pure spin-current injector.

关 键 词：Rashba spin-orbit coupling Andreev reflection pure spin current without net charge current 

分 类 号：O471.1[理学—半导体物理] TN201[理学—物理]