Virtual Parity-Time Symmetry

作     者：Huanan Li Ahmed Mekawy Alex Krasnok Andrea Alù 

作者机构：Photonics Initiative Advanced Science Research Center City University of New York New York New York 10031 USA Department of Electrical Engineering City College of The City University of New York New York New York 10031 USA Physics Program Graduate Center City University of New York New York New York 10016 USA 

出 版 物：《Physical Review Letters》 (物理评论快报)

年 卷 期：2020年第124卷第19期

页      面：193901-193901页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Air Force Office of Scientific Research, AFOSR Simons Foundation, SF 

主　　题：Metamaterials PT-symmetry Electromagnetic wave theory 

摘      要：Parity-time (PT) symmetry has recently been opening exciting directions in photonics, yet the required careful balance of loss and gain has been hindering its widespread applicability. Here, we propose a gain-free route to PT symmetry by extending it to complex-frequency excitations that can mimic gain in passive systems. Based on the concept of virtual absorption, extended here to implement also virtual gain, we implement PT symmetry in the complex-frequency plane and realize its landmark effects, such as broken phase transitions, anisotropic transmission resonances, and laser-absorber pairs, in a fully passive, hence inherently stable, system. These results open a path to establish PT symmetry and non-Hermitian physics in passive platforms.