论文标题
在图案化底物上声学拓扑边缘模式的微波阻抗显微镜成像
Microwave impedance microscopy imaging of acoustic topological edge mode on a patterned substrate
论文作者
论文摘要
我们已经研究了由linbo $ _3 $底物上的金属纳米柱组成的蜂窝声音晶体中的声学拓扑边缘模式。声带计算表明，尽管与底物的内部声学模式杂交，拓扑表面声波（SAW）模式仍居住在蜂窝声音晶体的边缘。脉搏型微波阻抗显微镜实现了两个相互倒置的拓扑音调晶体之间的Gigahertz拓扑边缘模式清晰可视化。频率依赖的图像表明，由于能量间隙的形成，与拓扑性质相一致，边缘模式随着体积锯模式被抑制而发展。在底物上简单的支柱结构中实现拓扑波导可能会为拓扑锯设备开发的新途径铺平道路。
We have studied acoustic topological edge modes in a honeycomb phononic crystal composed of metallic nano-pillars on a LiNbO$_3$ substrate. 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 realized clear visualization of the gigahertz topological edge mode between two mutually inverted topological phononic crystals. A frequency-dependent image showed 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.
