拓扑自旋光子晶体中螺旋边界态单向传输调控研究  

Unidirectional propagation control of helical edge states in topological spin photonic crystals

作　　者：隋文杰 张玉 张紫瑞 王小龙 张洪方[1,2] 史强 杨冰[1,2] Sui Wen-Jie;Zhang Yu;Zhang Zi-Rui;Wang Xiao-Long;Zhang Hong-Fang;Shi Qiang;Yang Bing(School of Physical Science and Information Engineering,Liaocheng University,Liaocheng 252000,China;Shandong Provincial Key Laboratory of Optical Communication Science and Technology,Liaocheng 252000,China)

机构地区：[1]聊城大学物理科学与信息工程学院,聊城252000 [2]山东省光通信科学与技术重点实验室,聊城252000

出　　处：《物理学报》2022年第19期103-114,共12页Acta Physica Sinica

基　　金：山东省自然科学基金(批准号:ZR2021MA091);山东省高校青创人才引育计划项目资助的课题。

摘　　要：利用二维拓扑自旋光子晶体中的螺旋边界态可以实现赝自旋锁定的光波的单向传输.尽管已有很多关于拓扑自旋光子晶体的研究,但对于其螺旋边界态的单向传输调控研究却很少.本文基于二维C_(6v)对称的拓扑自旋光子晶体结构,通过调整原胞中介电圆柱直径D以及圆柱与原胞中心的距离R,详细研究了系统的几何参数对拓扑自旋光子晶体的带隙结构、拓扑性质及其螺旋边界态单向传输性质调控的影响.结果表明,参数R对拓扑自旋光子晶体的带隙结构和拓扑性质有显著影响,D的改变会影响自旋光子晶体的带隙位置.螺旋边界态的结构及其单向传输性质与边界两侧自旋光子晶体带隙的拓扑性质及频带结构密切相关.在拓扑性质不变的情况下,改变边界两侧的光子晶体结构,也会改变螺旋边界态的结构及其单向传输性质.调整拓扑自旋光子晶体结构的几何参数R和D,就可以实现对螺旋边界态的单向传输性质的调控.该研究为拓扑自旋光子晶体螺旋边界态的选择和应用提供了参考.The unidirectional propagation of the pseudospin-locked optical waves can be achieved by using the helical edge states in two-dimensional topological spin photonic crystals.Although there have been lots of researches on topological spin photonic crystal,the unidirectional propagation regulation of helical edge states has been rarely studied up to now.Herein,by tuning the diameter D of the dielectric rod and the distance R between the center of the unit cell and the center of the rod in two-dimensional topological spin photonic crystal with C_(6v)symmetry,the effects of geometric parameters on the bandgap structure,topological properties and unidirectional propagation of helical edge states in topological spin photonics crystals are studied in detail.The results show that the parameter R has significant effects on the bandgap structure and topological properties of topological spin photonic crystal,and the diameter D of rod only affects the bandgap positions.The structures of helical edge states and their unidirectional propagations are closely related to the topological properties of the bandgaps and the frequency structures of photonic crystals on both sides of boundary.Without changing the topological properties of bandgaps,only changing the structures of the photonics crystals on either side of the boundary can also regulate the structures of the helical edge states and their unidirectional propagation.Thus,by adjusting the geometric parameters R and D of the topological spin photonic crystals,the helical edge states and their unidirectional propagations can be controlled.This study provides useful references for the selection and application of helical edge states in topological spin photonic crytals.

关 键 词：拓扑 自旋 光子晶体 边界态 

分 类 号：O734[理学—晶体学]