Topological Insulators by Topology Optimization

Abstract

An acoustic topological insulator (TI) is synthesized using topology optimization, a free material inverse design method. The TI appears spontaneously from the optimization process without imposing requirements on the existence of pseudo spin-1/2 states at the TI interface edge, or the Chern number of the topological phases. The resulting TI is passive; consisting of acoustically hard members placed in an air background and has an operational bandwidth of $\approx$12.5\% showing high transmission. Further analysis demonstrates confinement of more than 99\% of the total field intensity in the TI within at most six lattice constants from the TI interface. The proposed design hereby outperforms a reference from recent literature regarding energy transmission, field confinement and operational bandwidth.

6 pages, 5 figures

References in corpus (7)

• Topological Photonics
• Photonic Analogue of Two-dimensional Topological Insulators and Helical One-Way Edge Transport in Bi-Anisotropic Metamaterials
• Scheme to Achieve Silicon Topological Photonics
• Reflection-Free One-Way Edge Modes in a Gyromagnetic Photonic Crystal
• Topological Acoustics
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Cited by in corpus (6)

• Topological acoustics
• Inverse design of broadband and lossless topological photonic crystal waveguide modes
• Double Dirac Cones and Topologically Non-Trivial Phonons for Continuous, Square Symmetric (C${}_{4v}$ and C${}_{2v}$) Unit Cells
• Nonlinear nanophotonic devices in the Ultraviolet to Visible wavelength range
• Tuning acoustic impedance in load-bearing structures
• Liquid Structures: a novel Computational Fluid Dynamics (CFD) inspired metamaterial