Nanomechanical Measurement of the Brownian Force Noise in a Viscous Liquid
Nanomechanical Measurement of the Brownian Force Noise in a Viscous Liquid
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DOI：
10.1021/acs.nanolett.0c03766
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发表时间：
2021-01-13
期刊：
影响因子：
10.8
通讯作者：
Ekinci, Kamil L.
中科院分区：
文献类型：
--
作者：
Ari, Atakan B.;Hanay, M. Selim;Ekinci, Kamil L.
我们研究了粘性液体中纳米机械梁谐振器布朗运动所受热力的频谱。在第一组实验中，我们测量的功率谱密度（PSD）的位置波动的谐振器周围的基模在其中心。然后，我们测量谐振器的频率依赖性线性响应，再次在其中心，通过用与基模耦合良好的谐波力驱动它。这两个测量使我们能够确定作用在结构上的布朗力噪声在其基本模式的PSD。从多个谐振器跨越一个广泛的频率范围内的力噪声的PSD显示一个“彩色频谱”，并遵循耗散的叶片振荡的粘性液体凭借的波动耗散定理的统计力学。
We study the frequency spectrum of the thermal force giving rise to Brownian motion of a nanomechanical beam resonator in a viscous liquid. In the first set of experiments, we measure the power spectral density (PSD) of the position fluctuations of the resonator around its fundamental mode at its center. Then, we measure the frequency-dependent linear response of the resonator, again at its center, by driving it with a harmonic force that couples well to the fundamental mode. These two measurements allow us to determine the PSD of the Brownian force noise acting on the structure in its fundamental mode. The PSD of the force noise from multiple resonators spanning a broad frequency range displays a "colored spectrum" and follows the dissipation of a blade oscillating in a viscous liquid-by virtue of the fluctuation-dissipation theorem of statistical mechanics.