Observation of Flat Frequency Bands at Open Edges and Antiphase Boundary Seams in Topological Mechanical Metamaterials
arXiv:2005.06450 · doi:10.1103/PhysRevLett.125.225501
Abstract
Motivated by the recent theoretical studies on a two-dimensional (2D) chiral Hamiltonian based on the Su-Schrieffer-Heeger chains, we experimentally and computationally demonstrate that topological flat frequency bands can occur at open edges of 2D planar metamaterials and at antiphase boundary seams of ring-shaped or tubular metamaterials. Specifically, using mechanical systems made of magnetically coupled spinners, we reveal that the presence of the edge or seam bands that are flat in the entire projected reciprocal space follows the predictions based on topological winding numbers. The edge-to-edge distance sensitively controls the flatness of the edge bands and the localization of excitations. The analogue of the fractional charge state is also observed. Possible realizations of flat bands in a large class of metamaterials, including photonic crystals and electronic metamaterials, are discussed.
References in corpus (37)
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Moire bands in twisted double-layer graphene
- Tuning superconductivity in twisted bilayer graphene
- High temperature fractional quantum Hall states
- Fractional quantum Hall states at zero magnetic field
- Topolectrical circuit realization of topological corner modes
- Nearly-flat bands with nontrivial topology
- Observation of a localized flat-band state in a photonic Lieb lattice
- Topolectrical circuits
- Observation of bound states in Lieb photonic 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
- Origin of Mott insulating behavior and superconductivity in twisted bilayer graphene
- The Zak phase and the existence of edge states in graphene
- Artificial flat band systems: from lattice models to experiments
- Second-order photonic topological insulator with corner states
- Observation of the topological soliton state in the Su-Schrieffer-Heeger model
- Topologically protected midgap states in complex photonic lattices
- Nearly flat band with Chern number C=2 on the dice lattice
- Topological photonic crystal nanocavity laser
- Unconventional quantum optics in topological waveguide QED
- Observation of Quadrupole Transitions and Edge Mode Topology in an LC network
- Fractional Chern Insulators in Topological Flat bands with Higher Chern Number
- Fractional Quantum Hall Effect in Topological Flat Bands with Chern Number Two
- Su-Schrieffer-Heeger Model Inspired Acoustic Interface States and Edge States
- Electronic States of Graphene Grain Boundaries
- Theory and Experimental Investigation of the Quantum Valley Hall Effect
- Polariton condensation in - and -flatbands in a two-dimensional Lieb lattice
- Spectral imaging of topological edge states in plasmonic waveguide arrays
- Topological Photonic Tamm-States and the Su-Schrieffer-Heeger Model
- Topological Edge Modes by Smart Patterning
- Zak phase and band inversion in dimerized one-dimensional locally resonant metamaterials
- Experimental demonstration of the robust end state in a split-ring-resonator chain
- Compact Localized States in Engineered Flat-Band Metamaterials
- -fluxes, semi-metals and flat bands in artificial materials
- Flat Energy Bands within Antiphase and Twin Boundaries and at Open Edges in Topological Materials