Low-gain generalized PT symmetry for electromagnetic impurity-immunity via non-Hermitian doped zero-index materials  

作　　者：CUIPING LIU DONGYANG YAN BAOYIN SUN YADONG XU FANG CAO LEI GAO JIE LUO 

机构地区：[1]School of Physical Science and Technology&Collaborative Innovation Center of Suzhou Nano Science and Technology&Jiangsu Key Laboratory of Frontier Material Physics and Devices,Soochow University,Suzhou 215006,China [2]School of Optical and Electronic Information,Suzhou City University&Suzhou Key Laboratory of Biophotonics,Suzhou 215104,China

出　　处：《Photonics Research》2024年第11期2424-2434,共11页光子学研究(英文版)

基　　金：National Key Research and Development Program of China(2022YFA1404301);National Natural Science Foundation of China(11974010,12274313,12274314,12374293,12474313);Natural Science Foundation of Jiangsu Province(BK20221240,BK20221354);Suzhou Basic Research Project(SJC2023003);Undergraduate Training Program for Innovation and Entrepreneurship,Soochow University(202310285027Z)。

摘　　要：Parity-time-symmetric(PT-symmetric)metasurfaces exhibit a plethora of fascinating exceptional-point-induced phenomena,including unidirectional negative refraction and electromagnetic impurity-immunity.However,practical realization of these effects is often impeded by the high demand for gain metasurfaces(gain tangent∼10^(2)).Here,we propose a solution to this challenge by constructing a low-gain generalized PT-symmetric system.This is achieved by transforming the high-gain metasurface into a bulky slab and then realizing it utilizing zeroindex materials doped with low-gain dopants.Within this generalized PT-symmetric system,the required gain tangent of the dopants is only∼10^(−1)for the emergence of a coalesced exceptional point,where the remarkable property of electromagnetic impurity-immunity effect—perfect wave transmission regardless of impurities—appears.Furthermore,we observe a further decrease in demand for gain materials in an asymmetric environment.To validate this approach,a microwave implementation is demonstrated in full-wave simulations.This work provides a feasible strategy for substantially reducing requirements on gain materials in PT-symmetric systems,thereby enabling advanced electromagnetic wave control.

关 键 词：SYMMETRIC TANGENT exceptional 

分 类 号：O17[理学—数学]