Unidirectional electromagnetic windmill scattering in a magnetized gyromagnetic cylinder  

作　　者：Jianfeng Chen Jianbo Pan Yidong Zheng Wenyao Liang Zhi-Yuan Li 陈剑锋;潘剑波;郑义栋;梁文耀;李志远(School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510640,China;State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]School of Physics and Optoelectronics,South China University of Technology,Guangzhou 510640,China [2]State Key Laboratory of Luminescent Materials and Devices,South China University of Technology,Guangzhou 510640,China

出　　处：《Chinese Optics Letters》2022年第5期58-64,共7页中国光学快报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Nos.11974119 and 12074127);Science and Technology Project of Guangdong(No.2020B010190001);Science and Technology Program of Guangzhou(No.201904010105);Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06C594);National Key R&D Program of China(No.2018YFA0306200).

摘　　要：We present a discovery of an unusual unidirectionally rotating windmill scattering of electromagnetic waves by a magnetized gyromagnetic cylinder via an analytical theory for rigorous solution to fields and charges and an understanding of the underlying mathematical and physical mechanisms. Mathematically, the generation of nonzero off-diagonal components can break the symmetry of forward and backward scattering coefficients, producing unidirectional windmill scattering. Physically, this windmill scattering originates from the nonreciprocal unidirectional rotation of polarized magnetic charges on the surface of a magnetized gyromagnetic cylinder, which drives the scattering field to radiate outward in the radial direction and unidirectionally emit in the tangential direction. Interestingly, the unidirectional electromagnetic windmill scattering is insensitive to the excitation direction. Moreover, we also discuss the size dependence of unidirectional windmill scattering by calculating the scattering spectra of the gyromagnetic cylinder. These results are helpful for exploring and understanding novel interactions between electromagnetic waves and gyromagnetic materials or structures and offer deep insights for comprehending topological photonic states in gyromagnetic systems from the aspect of fundamental classical electrodynamics and electromagnetics.

关 键 词：unidirectional electromagnetic windmill scattering magnetized gyromagnetic cylinder topological photonics 

分 类 号：O441.4[理学—电磁学]