Imaging an Acoustic Topological Edge Mode on a Patterned Substrate with Microwave Impedance Microscopy
Imaging an Acoustic Topological Edge Mode on a Patterned Substrate with Microwave Impedance Microscopy
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DOI：
10.1103/physrevapplied.19.014001
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发表时间：
2023-01
影响因子：
4.6
通讯作者：
Y. Nii;Y. Onose
中科院分区：
文献类型：
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作者：
Y. Nii;Y. Onose
研究了由金属纳米柱构成的蜂窝状声子晶体中的声学拓扑边缘模.声学能带计算表明，拓扑表面声波（SAW）模式栖息在蜂窝声子晶体的边缘，尽管与基板的内部声学模式的杂交。脉冲型微波阻抗显微镜实现了两个相互倒置的拓扑声子晶体之间的千兆赫拓扑边缘模式的清晰可视化。一个频率依赖的图像显示，边缘模式的演变，因为大量的SAW模式被抑制，由于能隙的形成，符合拓扑性质。在衬底上的简单柱结构中实现拓扑波导可能为拓扑SAW器件的发展铺平了新的道路，用于广泛的用途，如量子计算，传感和通信应用。
We study acoustic topological edge modes in a honeycomb phononic crystal composed of metallic nanopillars on asubstrate. Acoustic band calculations show that the topological surface acoustic wave (SAW) mode inhabits the edge of the honeycomb phononic crystal in spite of the hybridization with the internal acoustic modes of the substrate. Pulse-type microwave impedance microscopy realizes clear visualization of the gigahertz topological edge mode between two mutually inverted topological phononic crystals. A frequency-dependent image shows that the edge mode evolves as the bulk SAW modes are suppressed owing to the energy gap formation, consistent with the topological nature. The realization of a topological waveguide in a simple pillar structure on a substrate might pave a new path to the development of topological SAW devices for a wide range of usages such as quantum computing, sensing, and communication applications.