锯齿形磷烯纳米带在光场驱动下的量子输运

Light-driven quantum transport of a zigzag phosphorene nanoribbon

为了拓宽磷烯纳米带的应用范围,基于紧束缚模型和Floquet理论,对锯齿形磷烯纳米带在周期光场驱动下的能带结构和电子输运性质进行了探究.结果表明:1)在光子能量大于体能隙的线偏振光照射下,体系的Floquet能谱会出现2个动态能隙,其能量范围依赖于光的频率和场强;2)若改变光的频率,使得导线的费米能进入某个动态能隙,则电导将从接近无光照的高值迅速降到零;3)当费米能位于导线的准平带内时,电导只是被辐照部分抑制.表明光场在磷烯纳米带中诱导的动态能隙会显著影响输运体系的电导,这有助于设计基于磷烯纳米带的光控器件.

In order to broaden the application range of phosphene nanoribbons,based on a tight-binding model and the Floquet theory,it was investigated the band structure and electron transport properties of a phosphorene nanoribbon under the periodic driving of light.The results showed that:1)Under the radiation of a linearly-polarized light with photon energy exceeding the bulk gap,two dynamical gaps appeared in the Floquet energy spectrum of the system.The energy range of dynamical gaps depended on the frequency and field intensity of the light;2)When the light frequency varied so that the Fermi energy of leads moved into a dynamical gap,the conductance changed quickly from a large value(approaching that under no radiation)to zero;3)For the Fermi energy lay in the quasi-flat band of the leads,the conductance was only partially suppressed by the radiation.The dynamical energy gap induced by the optical field affected greatly the conductance of the considered transport systems,which would be helpful for designing phosphorene nanoribbon based devices with light control.