The trained neural network directly connects the bandgap characteristics with the geometric param... more The trained neural network directly connects the bandgap characteristics with the geometric parameters. • The neural network finds out the object parameters accurately for inversely designing topological edge states. • Multiple scattering method is applied to simulate the direction selective topological edge states with wide bandgap. • The inverse design method has great potential applications for signal processing, sensing, and energy harvesting.
In recent years, the advances in topological insulator in the fields of condensed matter have bee... more In recent years, the advances in topological insulator in the fields of condensed matter have been extended to classical wave systems such as acoustic and elastic waves. However, the quantitative robustness study of topological states which is indispensable in practical realization is rarely reported. In this work, we proposed topologically protected edge states with zigzag, bridge and armchair interfaces in a new twisted phononic plate. The robustness of non-trivial band gap in bulk structure is clearly presented versus twisted angles, revealing a threshold of 5 degrees which is the key fundamental information for the robustness of topological edge states. We further defined a localized displacement ratio as an efficient parameter to characterize edge states. Due to the different orientation of the three interfaces, zigzag and bridge edge states show higher quantitative robustness in their localized displacement ratio. A map of robustness as a function of both frequency and twisted angle highlights the better performance of the topological zigzag edge state. Robustness is evaluated for twisted angle and for all possible types of interfaces for the first time, which benefits for the design and fabrication of solid functional devices with great potential applications.
Abstract Achieving strong robustness in elastic wave routing at subwavelength scale has always be... more Abstract Achieving strong robustness in elastic wave routing at subwavelength scale has always been a constant goal in practical applications such as energy harvesting, signal processing and sensor. Recently, topological phases have been widely extended from condensed matter physics to acoustics and mechanics to achieve robust control on the manipulation of acoustic and elastic waves. In this paper, we propose a chiral edge state at the interface between two subwavelength opposite chiral phononic crystals achieving edge state’s robustness higher than the design with the topological C 6v design. The unit cell consists of an array of pillars resonators on a plate arranged in a honeycomb configuration with a chiral variation of their resonant frequencies. It is shown that the robustness of the chiral edge states to defects and perturbations is stronger than that of the topological C 6v -symmetry waveguide systems. Furthermore, the harvesting powers of the chiral mechanical systems also show stronger robustness against the frequency disorder and the position disorder and are at least an order of magnitude higher than that of the C 6v designs. Our proposed chiral mechanical systems are foreseen to provide support for the design and manufacturing of miniaturized solid devices for vibration control and sensing.
The trained neural network directly connects the bandgap characteristics with the geometric param... more The trained neural network directly connects the bandgap characteristics with the geometric parameters. • The neural network finds out the object parameters accurately for inversely designing topological edge states. • Multiple scattering method is applied to simulate the direction selective topological edge states with wide bandgap. • The inverse design method has great potential applications for signal processing, sensing, and energy harvesting.
In recent years, the advances in topological insulator in the fields of condensed matter have bee... more In recent years, the advances in topological insulator in the fields of condensed matter have been extended to classical wave systems such as acoustic and elastic waves. However, the quantitative robustness study of topological states which is indispensable in practical realization is rarely reported. In this work, we proposed topologically protected edge states with zigzag, bridge and armchair interfaces in a new twisted phononic plate. The robustness of non-trivial band gap in bulk structure is clearly presented versus twisted angles, revealing a threshold of 5 degrees which is the key fundamental information for the robustness of topological edge states. We further defined a localized displacement ratio as an efficient parameter to characterize edge states. Due to the different orientation of the three interfaces, zigzag and bridge edge states show higher quantitative robustness in their localized displacement ratio. A map of robustness as a function of both frequency and twisted angle highlights the better performance of the topological zigzag edge state. Robustness is evaluated for twisted angle and for all possible types of interfaces for the first time, which benefits for the design and fabrication of solid functional devices with great potential applications.
Abstract Achieving strong robustness in elastic wave routing at subwavelength scale has always be... more Abstract Achieving strong robustness in elastic wave routing at subwavelength scale has always been a constant goal in practical applications such as energy harvesting, signal processing and sensor. Recently, topological phases have been widely extended from condensed matter physics to acoustics and mechanics to achieve robust control on the manipulation of acoustic and elastic waves. In this paper, we propose a chiral edge state at the interface between two subwavelength opposite chiral phononic crystals achieving edge state’s robustness higher than the design with the topological C 6v design. The unit cell consists of an array of pillars resonators on a plate arranged in a honeycomb configuration with a chiral variation of their resonant frequencies. It is shown that the robustness of the chiral edge states to defects and perturbations is stronger than that of the topological C 6v -symmetry waveguide systems. Furthermore, the harvesting powers of the chiral mechanical systems also show stronger robustness against the frequency disorder and the position disorder and are at least an order of magnitude higher than that of the C 6v designs. Our proposed chiral mechanical systems are foreseen to provide support for the design and manufacturing of miniaturized solid devices for vibration control and sensing.
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Papers by Zhihui Wen