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arXiv 1802.01906physics.app-phcond-mat.mes-hallcond-mat.mtrl-sci
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利用石墨烯谐振器检测超声振动

Detecting Ultrasound Vibrations by Graphene Resonators

G. J. Verbiest, J. N. Kirchhof, J. Sonntag, M. Goldsche, T. Khodkov, C. Stampfer

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18 pages, 12 figures, 1 table
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摘要：

超声检测是材料亚表面无损表征的重要手段之一，其目标是以纳米级甚至原子级的分辨率对亚表面结构进行横向分辨。近年来，石墨烯谐振器作为扬声器和超声收音机引起了人们的关注，显示出其实现空气传播超声通信系统的潜力。在这里，我们展示了一种石墨烯谐振器，它可以检测通过其制造的衬底传播的超声振动。在100~MHz的频率范围内，超声振幅的分辨率达到了$\approx7$ ~pm/ $\mathrm{\sqrt Hz}$。由于机械回复力的极高非线性，谐振频率本身也可以用于超声检测。在共振频率为65 MHz，振幅为100 μ m，分辨率为25 μ m的条件下，我们观察到了120 kHz的位移。值得注意的是，非线性也解释了通常观察到的不对称的谐振器的谐振频率调谐时，拉上静电门。这项工作提出了一种传感器的设计，适合到原子力显微镜悬臂，因此承诺在纳米级的非破坏性的表面下表征的直接超声检测。

英文摘要：

Ultrasound detection is one of the most important nondestructive subsurface characterization tools of materials, whose goal is to laterally resolve the subsurface structure with nanometer or even atomic resolution. In recent years, graphene resonators attracted attention as loudspeaker and ultrasound radio, showing its potential to realize communication systems with air-carried ultrasound. Here we show a graphene resonator that detects ultrasound vibrations propagating through the substrate on which it was fabricated. We achieve ultimately a resolution of $\approx7$~pm/$\mathrm{\sqrt Hz}$ in ultrasound amplitude at frequencies up to 100~MHz. Thanks to an extremely high nonlinearity in the mechanical restoring force, the resonance frequency itself can also be used for ultrasound detection. We observe a shift of 120~kHz at a resonance frequency of 65~MHz for an induced vibration amplitude of 100~pm with a resolution of 25~pm. Remarkably, the nonlinearity also explains the generally observed asymmetry in the resonance frequency tuning of the resonator when pulled upon with an electrostatic gate. This work puts forward a sensor design that fits onto an atomic force microscope cantilever and therefore promises direct ultrasound detection at the nanoscale for nondestructive subsurface characterization.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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