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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 toward exploring such non-Hermitian disorder driven topological insulators.
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Non-Hermitian topological light steering
Photonic topological insulators provide a route for disorder-immune light transport, which holds promise for practical applications. Flexible reconfiguration of topological light pathways can enable high-density photonics routing, thus sustaining the growing demand for data capacity. By strategically interfacing non-Hermitian and topological physics, we demonstrate arbitrary, robust light steering in reconfigurable non-Hermitian junctions, in which chiral topological states can propagate at an interface of the gain and loss domains. Our non-Hermitian–controlled topological state can enable the dynamic control of robust transmission links of light inside the bulk, fully using the entire footprint of a photonic topological insulator.
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- PAR ID:
- 10136843
- Date Published:
- Journal Name:
- Science
- Volume:
- 365
- Issue:
- 6458
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- 1163 to 1166
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1126/science.aay1064
