Fully spin-polarized, valley-polarized and spin-valley-polarized electron beam splitters utilizing zero-line modes in a three-terminal device  

作　　者：吕小龙 杨加恩 谢航 Xiao-Long Lü;Jia-En Yang;Hang Xie(College of Science,Guangxi University of Science and Technology,Liuzhou 545006,China;College of Physics,Chongqing University,Chongqing 401331,China;Chongqing Key Laboratory for Strongly-Coupled Physics,Chongqing University,Chongqing 401331,China)

机构地区：[1]College of Science,Guangxi University of Science and Technology,Liuzhou 545006,China [2]College of Physics,Chongqing University,Chongqing 401331,China [3]Chongqing Key Laboratory for Strongly-Coupled Physics,Chongqing University,Chongqing 401331,China

出　　处：《Chinese Physics B》2024年第6期596-603,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 12304058, 12204073, and 12147102);Guangxi Science and Technology Base and Talent Project (Grant No. 2022AC21077);Natural Science Foundation of Guangxi Province (Grant No. 2024GXNSFBA010229);Foundation of Guangxi University of Science and Technology (Grant No. 21Z52)。

摘　　要：Topological zero-line modes(ZLMs) with spin and valley degrees of freedom give rise to spin, valley and spinvalley transport, which support a platform for exploring quantum transport physics and potential applications in spintronic/valleytronic devices. In this work, we investigate the beam-splitting behaviors of the charge current due to the ZLMs in a three-terminal system. We show that with certain combinations of ZLMs, the incident charge current along the interface between different topological phases can be divided into different polarized currents with unit transmittance in two outgoing terminals. As a result, fully spin-polarized, valley-polarized and spin-valley-polarized electron beam splitters are generated. The mechanism of these splitters is attributed to the cooperative effects of the distribution of the ZLMs and the intervalley and intravalley scatterings that are modulated by the wave-vector mismatch and group velocity mismatch. Interestingly, half-quantized transmittance of these scatterings is found in a fully spin-valley-polarized electron beam splitter.Furthermore, the results indicate that these splitters can be applicable to graphene, silicene, germanene and stanene due to their robustness against the spin–orbit coupling. Our findings offer a new way to understand the transport mechanism and investigate the promising applications of ZLMs.

关 键 词：topological zero-line modes spin polarization valley polarization quantum transport 

分 类 号：O469[理学—凝聚态物理]