Topological scattering singularities and embedded eigenstates for polarization control and sensing applications  

作　　者：ZARKO SAKOTIC ALEX KRASNOK ANDREA ALú NIKOLINA JANKOVIC 

机构地区：[1]BioSense Institute-Research Institute for Information Technologies in Biosystems,University of Novi Sad,Dr Zorana Djindjica 1a 21101,Novi Sad,Serbia [2]Advanced Science Research Center,City University of New York,New York 10031,USA [3]Physics Program,Graduate Center,City University of New York,New York 10016,USA

出　　处：《Photonics Research》2021年第7期1310-1323,共14页光子学研究（英文版）

基　　金：Horizon 2020 Framework Programme(NOCTURNO 777714,ANTARES 739570);U.S.Department of Defense;Air Force Office of Scientific Research;National Science Foundation;Simons Foundation。

摘　　要：Epsilon-near-zero and epsilon near-pole materials enable reflective systems supporting a class of symmetryprotected and accidental embedded eigenstates (EEs) characterized by a diverging phase resonance. Here we show that pairs of topologically protected scattering singularities necessarily emerge from EEs when a non-Hermitian parameter is introduced,lifting the degeneracy between oppositely charged singularities. The underlying topological charges are characterized by an integer winding number and appear as phase vortices of the complex reflection coefficient. By creating and annihilating them,we show that these singularities obey charge conservation,and provide versatile control of amplitude,phase,and polarization in reflection,with potential applications for polarization control and sensing.

关 键 词：TOPOLOGICAL protected INTEGER 

分 类 号：O469[理学—凝聚态物理]