Anisotropic and valley-resolved beamsplitter based on a tilted Dirac system  

作　　者：Xixuan Zhou Jianlong Zheng Feng Zhai Xixuan Zhou;郑建龙;Feng Zhai(Department of Physics,Zhejiang Normal University,Jinhua 321004,China)

机构地区：[1]Department of Physics,Zhejiang Normal University,Jinhua 321004,China

出　　处：《Communications in Theoretical Physics》2022年第7期138-145,共8页理论物理通讯（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.11774314)。

摘　　要：We investigate theoretically valley-resolved lateral shift of electrons traversing an n–p–n junction bulit on a typical tilted Dirac system(8-Pmmn borophene). A gauge-invariant formula on Goos–H?nchen(GH) shift of transmitted beams is derived, which holds for any anisotropic isoenergy surface. The tilt term brings valley dependence of relative position between the isoenergy surface in n region and that in the p region. Consequently, valley double refraction can occur at the n–p interface. The exiting positions of two valley-polarized beams depend on the incident angle and energy of incident beam and barrier parameters. Their spatial distance D can be enhanced to be ten to a hundred times larger than the barrier width. Due to tilting-induced high anisotropy of the isoenergy surface, D depends strongly on the barrier orientation. It is always zero when the junction is along the tilt direction of Dirac cones. Thus GH effect of transmitted beams in tilted Dirac systems can be utilized to design anisotropic and valleyresolved beam-splitter.

关 键 词：Goos-H?nchen shift anisotropic isoenergy surface 8-Pmmn borophene valley double refraction 

分 类 号：O43[机械工程—光学工程]