Department of Applied Physics, Chalmers University of Technology, Göteborg, Sweden.
J Phys Condens Matter. 2012 Nov 28;24(47):475301. doi: 10.1088/0953-8984/24/47/475301. Epub 2012 Oct 26.
This paper presents a study of dephasing of an underdamped nanomechanical resonator subject to random mass loading of small particles. A frequency noise model is presented which describes dephasing due to the attachment and detachment of particles at random points and particle diffusion along the resonator. This situation is commonly encountered in current mass measurement experiments using nanoelectromechanical (NEM) resonators. The conditions which can lead to inhomogeneous broadening and fine structure in the modes' absorption spectra are discussed. It is also shown that the spectra of the higher-order cumulants of the (complex) vibrational mode amplitude are sensitive to the parameters characterizing the frequency noise process. Hence, measurement of these cumulants can provide information not only about the mass but also about other parameters of the particles (diffusion coefficient and attachment-detachment rates).
本文研究了在小颗粒随机质量加载下欠阻尼纳米机械谐振器的退相。提出了一个频率噪声模型，该模型描述了由于粒子在随机点的附着和脱附以及粒子沿谐振器扩散而导致的退相。这种情况在当前使用纳米机电（NEM）谐振器进行质量测量实验中很常见。讨论了导致模式吸收谱中不均匀展宽和精细结构的条件。还表明，（复）振动模式幅度的高阶累积量的谱对表征频率噪声过程的参数敏感。因此，这些累积量的测量不仅可以提供关于质量的信息，还可以提供关于粒子的其他参数（扩散系数和附着-脱附速率）的信息。
