Realization of a Z classified chiral-symmetric higher-order topological insulator in a coupling-inversion acoustic crystal

Abstract

Higher-order topological band theory has transformed the landscape of topological phases in quantum and classical systems. Here, we experimentally demonstrate a two-dimensional (2D) higher-order topological phase (HOTP), referred to as the multiple chiral topological phase (MCTP), which is protected by a multipole chiral number (MCN). Our realization differs from previous HOTPs in that it possesses a larger-than-unity MCN, which arises when the nearest-neighbor couplings (NNCs) are weaker than long-range couplings (LRCs). Our phase has an MCN of 4, protecting the existence of 4 mid-gap topological corner modes (TCMs) at each corner. The multiple TCMs demonstrated here could lead to enhanced quantum-inspired devices for sensing and computing. Our study also highlights the rich and untapped potential of LRC manipulation for future research in topological phases.

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Cited by in corpus (12)

• Topologically protected vortex transport via chiral-symmetric disclination
• Higher-order topological phases in crystalline and non-crystalline systems: a review
• Observation of Topological Corner State Arrays in Photonic Quasicrystals
• Revealing the spatial nature of sublattice symmetry
• Multi higher-order Dirac and nodal line semimetals
• Probing Chiral-Symmetric Higher-Order Topological Insulators with Multipole Winding Number
• Unveiling Higher-Order Topology via Polarized Topological Charges
• Topological Corner States in Bilayer and Trilayer Systems with Vertically Stacked Topological Heterostructures
• A new class of higher-order topological insulators that localize energy at arbitrary multiple sites
• Topology reconstruction for asymmetric systems by isomorphic mapping or perturbation approximation
• Multiple topological corner states in the continuum of extended kagome lattice
• Non-Hermitian second-order topological insulator with point gap