窄—宽—窄形量子线的电子自旋极化输运性质

Spin-polarization Electron Transport Properties of the Narrow-wide-narrow Quantum Wire

本文对含Rashba自旋轨道耦合(spin-orbit coupling,SOC)的窄—宽—窄形量子线的电子自旋极化输运性质进行了理论研究。利用晶格格林函数法,计算出该量子线结构和SOC会产生势阱,进而使系统产生束缚态,导致该系统电导呈现Fano共振结构,在相应的自旋极化率中同时也出现了Fano共振或反共振。当自旋向上的电子极化入射时,在出射端会出现高达-0.99,0.99的自旋极化率;当系统结构参数变化时,自旋极化率会出现周期性变化或正弦变化。

In this paper,the arrow-wide-narrow form of the quantum wire is studied by lattice green function method.It was found that spin-orbital coupling can produce not only potential trap,but also bound states,which may result in Fano resonant conductance structure.The spin polarization rate is introduced by Fano resonance or antiresonance.In our model,when the spin-polarized electrons injected from the input lead,the electron spin polarization rate will be as high as the 0.99 in the output lead.And when the system structure parameters change,in the output lead,spin polarization rate will be changed periodically just like the form of sine function.