Topological edge states in acoustic Kagome lattices
Open Access
- 1 May 2017
- journal article
- research article
- Published by IOP Publishing in New Journal of Physics
- Vol. 19 (5), 055002
- https://doi.org/10.1088/1367-2630/aa6996
Abstract
We demonstrate that an acoustic Kagome lattice formed by an array of interconnected resonant cavities exhibits a new class of topological states protected by C3 symmetry, and it is characterised by a topological invariant in the form of a winding number in Pauli vector space. This acoustic topological metamaterial can be considered as the two-dimensional analogue of the Su–Schrieffer–Heeger model, exhibiting a topological transition when a detuning is introduced between the inter-cell and intra-cell hopping amplitudes. The topological transition caused by such detuning is accompanied by the opening of a complete topological band gap, which may host edge states. The edge states emerge on either truncated ends of the lattice terminated by a cladding layer or at the domain walls between topologically nontrivial and trivial domains. First-principles simulations based on full-wave finite element method are used to design the lattice and confirm our analytical predictions.Keywords
Funding Information
- Russian Science Foundation (16-19-10538)
- Natural Science Foundation of USA (CMMI-1537294, EFRI-1641069)
- Simons Foundation
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