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arXiv 1802.07217cond-mat.mes-hall
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测量非线性纳米机械谐振器中的频率起伏

Measuring frequency fluctuations in nonlinear nanomechanical resonators

Olivier Maillet, Xin Zhou, Rasul R. Gazizulin, Bojan R. Ilic, Jeevak M. Parpia, Olivier Bourgeois, Andrew D. Fefferman, Eddy Collin

摘要:

近年来,纳米力学的进展已经证明了器件范围的不断扩大,从自上而下的结构到吸引人的自下而上的MoS $_2$和石墨烯膜,用于传感和面向组件的应用。所有这些器件的主要问题之一是频率噪声,这最终限制了它们的适用性。这个问题最近引起了很多关注,这种噪音的起源至今仍然难以捉摸。在这封信中,我们提出了一个非常简单的技术来测量非线性机械设备中的频率噪声,基于双稳态的存在。这是说明氮化硅高应力双固支梁,在低温环境中。我们报告相同的$T/f$依赖的频率噪声功率谱的文献中报道的。但我们也发现了意想不到的{ \it阻尼波动},放大的分叉点附近,这种效果是明显不同于已经报道的非线性失相,并提出了一个基本的限制分叉频率的测量。该技术进一步应用于测量频率噪声作为模式数的函数,在同一设备内。基本弯曲$δf/f_0$的相对频率噪声在$0.5 - 0.01~$ ppm范围内(与低温MHz器件的文献一致),并随研究范围内的模式数而减小。该技术可以应用于{ \it任何类型}的纳米机械结构,使这些设备中的固有噪声源的理解的进展。

英文摘要:

Advances in nanomechanics within recent years have demonstrated an always expanding range of devices, from top-down structures to appealing bottom-up MoS$_2$ and graphene membranes, used for both sensing and component-oriented applications. One of the main concerns in all of these devices is frequency noise, which ultimately limits their applicability. This issue has attracted a lot of attention recently, and the origin of this noise remains elusive up to date. In this Letter we present a very simple technique to measure frequency noise in nonlinear mechanical devices, based on the presence of bistability. It is illustrated on silicon-nitride high-stress doubly-clamped beams, in a cryogenic environment. We report on the same $T/f$ dependence of the frequency noise power spectra as reported in the literature. But we also find unexpected {\it damping fluctuations}, amplified in the vicinity of the bifurcation points; this effect is clearly distinct from already reported nonlinear dephasing, and poses a fundamental limit on the measurement of bifurcation frequencies. The technique is further applied to the measurement of frequency noise as a function of mode number, within the same device. The relative frequency noise for the fundamental flexure $δf/f_0$ lies in the range $0.5 - 0.01~$ppm (consistent with literature for cryogenic MHz devices), and decreases with mode number in the range studied. The technique can be applied to {\it any types} of nano-mechanical structures, enabling progresses towards the understanding of intrinsic sources of noise in these devices.

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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