Topologically protected elastic waves in phononic metamaterials

By Hossein Mousavi, Alexander B. Khanikaev, Z. Wang. Nature Communications, 2015

722 citations recorded by the source corpus.

Surface waves in topological states of quantum matter exhibit unique protection from backscattering induced by disorders, making them ideal carriers for both classical and quantum information. Topological matters for electrons and photons are largely limited by the range of bulk properties, and the associated performance trade-offs. In contrast, phononic metamaterials provide access to a much wider range of material properties. Here we demonstrate numerically a phononic topological metamaterial in an elastic-wave analogue of the quantum spin Hall effect. A dual-scale phononic crystal slab is used to support two effective spins for phonons over a broad bandwidth, and strong spin–orbit coupling is realized by breaking spatial mirror symmetry. By preserving the spin polarization with an external load or spatial symmetry, phononic edge states are shown to be robust against scattering from discrete defects as well as disorders in the continuum, demonstrating topological protection for phonons in both static and time-dependent regimes. Metamaterials are engineered media with properties that mimic those of natural materials, but offer a much wider range of possibilities. Here, the authors numerically demonstrate an elastic-wave analogue of the quantum spin Hall effect in a phononic topological metamaterial.

Subfields: Atomic and Molecular Physics, and Optics, Biomedical Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/752ca72919d4deac68cf963288537b19dc8aeed9

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Citations in the corpus

Tailoring Structure‐Borne Sound through Bandgap Engineering in Phononic Crystals and Metamaterials: A Comprehensive Review (2022, background): “4 quantum spin Hall effect [165], elastic Valley-Hall edge states [166,167], and elastic higher-order topological insulator with topologically protected corner states [168].”
Topological Photonic Crystals: Physics, Designs, and Applications (2022, background): “Recently, topology has been widely applied in different fields, including condensed matter [1-6], cold atom [7, 8], acoustics [9-13] and mechanics [14-16].”
Three-dimensional all-dielectric photonic topological insulator (2016, background): “Following the footsteps of condensed matter topological systems, a significant progress has been recently made in understanding and realizing topological states for bosons [ 1, 2, 3, 4, 5] and in classical systems [ 6, 7, 8, 9, 10, 11, 12, 13, 14 15, 16, 17, 18, 19, 20, 21, 22, 23].”
A study of topological effects in 1D and 2D mechanical lattices (2018, background): “…other insulators, such as the quantum Hall ( Chen and Wu, 2016; Fleury et al., 2016; Nash et al., 2015; Yang et al., 2015 ) and the quantum spin Hall insulators ( Mousavi et al., 2015; Süsstrunk and Huber, 2015; Yves et al., 2017a; 2017b ), have been implemented in more general 2D geometries.”
Experimental Observation of Topologically Protected Helical Edge Modes in Patterned Elastic Plates (2018, methodology): “[22], where a deep subwavelength patterning in a dual-scale phononic slab is considered.”
Exceptional topology of non-Hermitian systems (2019, positive): “…have been shown to host phononic edge states in microtubules (Prodan and Prodan, 2009), quantum-spin-Hall edge states in the form of elastic waves (Mousavi, Khanikaev, and Wang, 2015), and surface acoustic waves with negative refraction index on the surfaces of a phononic version of a Weyl…”