Controllable and switchable chiral near-fields in symmetric graphene metasurfaces  

作　　者：Li Hu Hongxia Dai Fayin Cheng Yuxia Tang 胡莉;代洪霞;程发银;唐裕霞(Chongqing Key Laboratory of Intelligent Perception and BlockChain Technology,Chongqing Technology and Business University,Chongqing 400067,China;Department of Applied Physics,School of Computer Science and Information Engineering,Chongqing Technology and Business University,Chongqing 400067,China;Soft Matter and Interdisciplinary Research Center,College of Physics,Chongqing University,Chongqing 400044,China)

机构地区：[1]Chongqing Key Laboratory of Intelligent Perception and BlockChain Technology,Chongqing Technology and Business University,Chongqing 400067,China [2]Department of Applied Physics,School of Computer Science and Information Engineering,Chongqing Technology and Business University,Chongqing 400067,China [3]Soft Matter and Interdisciplinary Research Center,College of Physics,Chongqing University,Chongqing 400044,China

出　　处：《Chinese Physics B》2021年第12期563-570,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11804035);Science and Technology Research Program of Chongqing Municipal Education Commission,China(Grant No.KJ1706153)。

摘　　要：A strong chiral near-field plays significant roles in the detection,separation and sensing of chiral molecules.In this paper,a simple and symmetric metasurface is proposed to generate strong chiral near-fields with both circularly polarized light and linearly polarized light illuminations in the mid-infrared region.Owing to the near-field interaction between plasmonic resonant modes of two nanosheets excited by circularly polarized light,there is a strong single-handed chiral near-field in the gap between the two graphene nanosheets and the maximum enhancement of the optical chirality could reach two orders of magnitude.As expected,the intensity and the response wavelength of the chiral near-fields could be controlled by the Fermi level and geometrical parameters of the graphene nanosheets,as well as the permittivity of the substrate.Meanwhile,based on the interaction between the incident field and scattered field,the one-handed chiral nearfield in the gap also could be generated by the linearly polarized light excitation.For the two cases,the handedness of the chiral near-field could be switched by the polarized direction of the incident light.These results have potential opportunities for applications in molecular detection and sensing.

关 键 词：plasmonic resonance chiral near-field GRAPHENE metasurface 

分 类 号：O469[理学—凝聚态物理]