电磁波辐照下量子线的电子自旋极化输运性质  

Spin polarized transport properties for quantum wire irradiated by THz electromagnetic wave

作　　者：肖贤波[1] 李小毛[1] 周光辉[2] 

机构地区：[1]江西农业大学物理系,南昌330045 [2]湖南师范大学物理系,长沙410081

出　　处：《物理学报》2007年第3期1649-1654,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574042)资助的课题.~~

摘　　要：理论上研究Rashba自旋-轨道相互作(SOI)量子线在外电磁波辐照下的电子自旋极化输运性质.在自由电子模型下利用散射矩阵方法,发现当RashbaSOI较弱时,自旋极化率与外电磁场频率和电子入射能量无关,而当RashbaSOI较强时,自旋极化率则强烈依赖于外场频率和电子入射能量,其物理根源是RashbaSOI使子带混合引起的.此外,当电子的入射能量增加到打开另一通道阈值时,电子的透射率出现一个反常的台阶结构,这来源于电子与光子的非弹性散射而使电子在子带间的跃迁.We theoretically study the spin-polarized electron transport properties of a quantum wire under irradiation of a transversely polarized external electromagnetic （EM） wave in the presence of Rashba spin-orbit interaction （SOI）. Using the free-electron model and the scattering matrix approach, we show that spin polarization is independent on the EM frequency and the electron incident energy when Rashba SOI is weak, while it is strongly dependent on the EM frequency and the incident energy when Rashba SOI is comparatively strong. In addition, an unusual step-structure appears in the electronic transmission probability as the incident energy increases to a threshold value when a coherent EM field is applied. We demonstrate that the first effect comes from Rashba subband intermixing and the latter comes from inelastic scattering of electrons with lateral photons through intersubband transitions.

关 键 词：量子线 电磁波 自旋极化输运 散射矩阵 

分 类 号：O471[理学—半导体物理]