Spin Filter Based on an Aharonov-Bohm Interferometer with Rashba Spin-Orbit Effect  

作　　者：方明 孙连亮 

机构地区：[1]Department of Physics and Institute of Graduate Students, Bohai University, Jinzhou 121000 [2]College of Science, North China University of Technology, Beijing 100041

出　　处：《Chinese Physics Letters》2008年第9期3389-3392,共4页中国物理快报（英文版）

摘　　要：We propose a spin filter based on both the quantum interference and the Rashba spin-orbit （RSO） effects. This spin filter consists of a Aharonov-Bohm （AB） interferometer with two quantum dots （QDs） inserted in its arms. The influences of a magnetic flux φ threading through the AB ring and the RSO interaction inside the two QDs are taken into account by using the nonequilibrium Green＇s function technique. Due to the existence of the RSO interaction, the electrons flowing through different arms of the ring will acquire a spin-dependent phase factor in the linewidth matrix elements. This phase factor, combined with the influence of the magnetic flux, will induce a spin-dependent electron transport through the device. Moreover, we show that by tuning the magnetic flux, the RSO strength and the inter-dot tunnelling coupling strength, a pure spin-up or spin-down conductance can be obtained when a spin-unpolarized current is injected from the external leads, which can be used to filter the electron spin.We propose a spin filter based on both the quantum interference and the Rashba spin-orbit （RSO） effects. This spin filter consists of a Aharonov-Bohm （AB） interferometer with two quantum dots （QDs） inserted in its arms. The influences of a magnetic flux φ threading through the AB ring and the RSO interaction inside the two QDs are taken into account by using the nonequilibrium Green＇s function technique. Due to the existence of the RSO interaction, the electrons flowing through different arms of the ring will acquire a spin-dependent phase factor in the linewidth matrix elements. This phase factor, combined with the influence of the magnetic flux, will induce a spin-dependent electron transport through the device. Moreover, we show that by tuning the magnetic flux, the RSO strength and the inter-dot tunnelling coupling strength, a pure spin-up or spin-down conductance can be obtained when a spin-unpolarized current is injected from the external leads, which can be used to filter the electron spin.

分 类 号：O471[理学—半导体物理]