Topological Anderson Insulator in Disordered Photonic Crystals

• DOI: 10.1103/physrevlett.125.133603
• Publication Date: 2020-09-24T16:01:41Z
• Authors: Gui-Geng Liu; Yihao Yang; Xin Ren; Haoran Xue; Xiao Lin; Yuan-Hang Hu; Hong-xiang Sun; Bo Peng; Peiheng Zhou; Yidong Chong; Baile Zhang
• Keywords: :Physics [Science]; Photonic Crystals; 0103 physical sciences; Anderson Insulator; 01 natural sciences

Recent studies have revealed the counterintuitive possibility that increasing disorder can turn a topologically trivial insulator into a nontrivial insulator, called a topological Anderson insulator (TAI). Here, we propose and experimentally demonstrate a photonic TAI in a two-dimensional disordered gyromagnetic photonic crystal in the microwave regime. We directly observe the disorder-induced topological phase transition from a trivial insulator to a TAI with robust chiral edge states. We also demonstrate topological heterostructures that host edge states at interfaces between domains with different disorder parameters.