Year: 2021
Type: article
Abstract: Symmetries play a major role in identifying topological phases of matter and in establishing a direct connection between protected edge states and topological bulk invariants via the bulk-boundary correspondence. One-dimensional lattices are deemed to be protected by chiral symmetry, exhibiting quantized Zak phases and protected edge states, but not for all cases. Here, we experimentally realize an extended Su-Schrieffer-Heeger model with broken chiral symmetry by engineering one-dimensional zigzag photonic lattices, where the long-range hopping breaks chiral symmetry but ensures the existence of inversion symmetry. By the averaged mean displacement method, we detect topological invariants directly in the bulk through the continuous-time quantum walk of photons. Our results demonstrate that inversion symmetry protects the quantized Zak phase but edge states can disappear in the topological nontrivial phase, thus breaking the conventional bulk-boundary correspondence. Our photonic lattice provides a useful platform to study the interplay among topological phases, symmetries, and the bulk-boundary correspondence.
Source: Physical Review Letters
Institutions: University of Science and Technology of China, Shanghai Jiao Tong University, State Key Laboratory of Advanced Optical Communication Systems and Networks, State Key Laboratory of Advanced Optical Communication Systems and Networks, Consejo Superior de Investigaciones Científicas, Institute for Cross-Disciplinary Physics and Complex Systems, Politecnico di Milano
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Natural Science Foundation of China, Shanghai Municipal Education Commission, Science and Technology Commission of Shanghai Municipality, Shanghai Jiao Tong University, National Key Research and Development Program of China, Zhiyuan Innovative Research Center, Shanghai Jiao Tong University
OpenAlex ID: W3203231981