Observation of Topological Corner State Arrays in Photonic Quasicrystals

Abstract

Recently, the studies of topological corner states (TCSs) are extended from crystals to quasicrystals, which are referred to as higher-order topological quasicrystalline insulators (HOTQIs). However, the TCSs of complete quasi-periodic structure in photonic systems have yet to be demonstrated. Moreover, there is only one TCS in each corner region in higher-order topological insulators (HOTIs). Increasing the number of TCS is expected to increase application potential of TCSs. In this work, HOTQIs in photonic systems are experimentally observed. It is found that HOTQIs possess TCS arrays, and each TCS array contains several TCSs. Furthermore, the universal theoretical framework of the multimer analysis method is improved, and the difference in the average charge density is proposed as a real-space topological index. These results will open up new ideas for investigating highly integrated, multi-region localized TCSs and are expected to provide new ways to explore topological phenomena and the applications of photonic quasicrystals.

References in corpus (24)

• Electric Multipole Moments, Topological Multipole Moment Pumping, and Chiral Hinge States in Crystalline Insulators
• Observation of topological valley transport of sound in sonic crystals
• Higher-order topological insulators and semimetals on the breathing Kagome and pyrochlore lattices
• Visualization of higher-order topological insulating phases in two-dimensional dielectric photonic crystals
• Direct observation of corner states in second-order topological photonic crystal slabs
• Classical higher-order topological insulators
• Experimental discovery of bulk-disclination correspondence
• Low-threshold topological nanolasers based on second-order corner state
• A fractional corner anomaly reveals higher-order topology
• Observation of a higher-order topological bound state in the continuum
• Chiral-Symmetric Higher-Order Topological Phases of Matter
• Experimental realization of single-plaquette gauge flux insertion and topological Wannier cycles
• Coupled cavity-waveguide system based on topological corner state and edge state
• Topological dislocation modes in three-dimensional acoustic topological insulators
• Higher-Order topological insulator in a dodecagonal quasicrystal
• Observation of degenerate zero-energy topological states at disclinations in an acoustic lattice
• A Universal Mirror-stacking Approach for Constructing Topological Bound States in the Continuum
• Effective Model for Fractional Topological Corner Modes in Quasicrystals
• Topological states in quasicrystals
• Realization of quasicrystalline quadrupole topological insulators in electrical circuits
• Realization of a Z classified chiral-symmetric higher-order topological insulator in a coupling-inversion acoustic crystal
• Topological photonic crystal fibers based on second-order corner modes
• Chiral photonic topological states in Penrose quasicrystals
• Role of the edges in a quasicrystalline Haldane model

Cited by in corpus (3)

• Hybrid skin-topological effect induced by eight-site cells and arbitrary adjustment of the localization of topological edge states
• Higher-order topology in twisted multilayer systems: a review
• Topological Corner States in Bilayer and Trilayer Systems with Vertically Stacked Topological Heterostructures