Dispersion tuning and route reconfiguration of acoustic waves in valley topological phononic crystals
Dispersion tuning and route reconfiguration of acoustic waves in valley topological phononic crystals
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DOI：
10.1038/s41467-020-14553-0
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发表时间：
2020-02-07
影响因子：
16.6
通讯作者：
Jun Huang, Tony
中科院分区：
文献类型：
--
作者：
Tian, Zhenhua;Shen, Chen;Jun Huang, Tony
谷自由度在晶体中提供了很大的潜力，操纵经典波，然而，很少有研究调查谷态与复杂的波数，谷态梯度系统，或谷态的色散调谐。在这里，我们提出了可调谷声子晶体（PC）的混合通道腔室组成的三个可调参数。我们的PC支持谷态和具有复杂波数的狄拉克锥。它们可以被配置为形成啁啾谷PC，其中边缘模式被减慢到零群速度状态，其中不同频率的能量在不同的指定位置处积累。它们实现了多种功能，包括谷态色散关系的调谐、表面声波的鲁棒路由以及群速度的空间调制。这项工作可能会引发未来的调查与复杂的波数在其他经典系统的拓扑状态，在梯度材料的拓扑状态的进一步研究，以及声学器件的发展。
The valley degree of freedom in crystals offers great potential for manipulating classical waves, however, few studies have investigated valley states with complex wavenumbers, valley states in graded systems, or dispersion tuning for valley states. Here, we present tunable valley phononic crystals (PCs) composed of hybrid channel-cavity cells with three tunable parameters. Our PCs support valley states and Dirac cones with complex wavenumbers. They can be configured to form chirped valley PCs in which edge modes are slowed to zero group velocity states, where the energy at different frequencies accumulates at different designated locations. They enable multiple functionalities, including tuning of dispersion relations for valley states, robust routing of surface acoustic waves, and spatial modulation of group velocities. This work may spark future investigations of topological states with complex wavenumbers in other classical systems, further study of topological states in graded materials, and the development of acoustic devices.