Electrically Tunable Graphene Terahertz Isolator Assisted by Nonreciprocal Plasmon  

作　　者：Chen-Ran Xu Weiru Fan Yanhao Tang Dawei Wang 徐晨燃;范伟如;汤衍浩;王大伟(School of Physics,Zhejiang University,Hangzhou 310027,China;Zhejiang Key Laboratory of Micro-Nano Quantum Chips and Quantum Control,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]School of Physics,Zhejiang University,Hangzhou 310027,China [2]Zhejiang Key Laboratory of Micro-Nano Quantum Chips and Quantum Control,Zhejiang University,Hangzhou 310027,China

出　　处：《Chinese Physics Letters》2025年第1期58-67,共10页中国物理快报(英文版)

基　　金：Supported by the National Natural Science Foundation of China(Grant Nos.11934011 and 12274365);National Key R&D Program of China(Grant Nos.2022YFA1402400 and 2022YFA1400043);Zhejiang Provincial Natural Science Foundation of China(Grant No.LR24A040001);Open project of Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education)of Shanghai Jiao Tong University。

摘　　要：Nonreciprocal isolators enable unidirectional light propagation without back-reflection.Typical terahertz isolators require magnetic fields to break the time-reversal symmetry.Herein,we propose a nonmagnetic isolator in the terahertz range based on nonreciprocal graphene plasmons operated in a reflection configuration.The bias voltage generates a drift current in graphene,which breaks the time-reversal symmetry and induces nonreciprocal reflection.The isolator device exhibited a high isolation exceeding 20 d B with an insertion loss of less than 3 d B.Moreover,the bandwidth wit isolation exceeding 20 d B can be broadened five times to 1.7 THz by tuning the carrier density.The indexes,including the isolation,insertion loss and bandwidth of the isolator,show a strong dependence on the drift velocity and mobility of graphene,as well as the air-gap thickness.Our study shows great potential in the burgeoning terahertz technology,where nonmagnetic and electrically tunable isolators are still lacking.

关 键 词：tuning reciprocal EXCEEDING 

分 类 号：O53[理学—等离子体物理] O441.4[理学—物理]