2019/12/23 by Xi-Wang Luo, Luo, Xi-Wang, Chuanwei Zhang +1
Physics and Astronomy · #Advanced Fiber Laser Technologies #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Optics (physics.optics) #Quantum Mechanics and Non-Hermitian Physics #Quantum Physics (quant-ph) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1912.10652
openalex publication_date 2019/12/23 · openalex created_date 2022/12/25 · openalex updated_date 2026/07/28
Recent studies of disorder or non-Hermiticity induced topological insulators inject new ingredients for engineering topological matter. Here we consider the effect of purely non-Hermitian disorders, a combination of these two ingredients, in a 1D coupled-cavity array with disordered gain and loss. Topological photonic states can be induced by increasing gain-loss disorder strength with topological invariants carried by localized states in the complex bulk spectra. The system showcases rich phase diagrams and distinct topological states from Hermitian disorders. The non-Hermitian critical behavior is characterized by the biorthogonal localization length of zero-energy edge modes, which diverges at the critical transition point and establishes the bulk-edge correspondence. Furthermore, we show that the bulk topology may be experimentally accessed by measuring the biorthogonal chiral displacement, which can be extracted from a proper Ramsey interferometer that works in both clean and disordered regions. The proposed coupled-cavity photonic setup relies on techniques that have been experimentally demonstrated, and thus provides a feasible route towards exploring such non-Hermitian disorder driven topological insulators.