在考虑自旋轨道耦合的情况下,研究了通过一非磁性半导体异质结的太赫兹光子驱动的电子输运,研究结果显示频率相关的电导谱出现不对称的Fano型共振的劈裂;随着振荡场幅度的增加,多光子辅助过程出现;通过改变外加场参数,可以实现自旋过滤目的,特别是在干涉相消Fano型共振的频率位置时,出现了100%纯的自旋极化流.这些属性有助于大范围可调的自旋过滤器的实现并且可以得到纯的自旋透射流.
We investigate theoretically the intense terahertz field-driven electron-transport through a nonmagnetic semiconductor-heterostructure with spin-orbit coupling.It is found that the frequency-dependent conductivity spectra possess splitting resonance-peaks of asymmetric Fano-type,and multiple-photon-process arises with the increasing amplitude of oscillating field.By changing the external field parameters,the purpose of spin filtering may be realized,and 100% pure spin-polarized current at the frequency of Fano-resonance can also be achieved.These interesting features may be a very useful basis for devising a wide range tunable spin filter and realizing pure spin current.