Mass loading induced dephasing in nanomechanical resonators

• Published in: Journal of physics. Condensed matter Vol. 24; no. 47; pp. 475301 - 7
• Main Author: Atalaya, Juan
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 28.11.2012; Institute of Physics
• Subjects: Attachment; Condensed matter; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mathematical models; Mechanical instruments, equipment and techniques; mechanical resonators; Micromechanical devices and systems; Nanostructure; Noise; Particles (of physics); Physics; resolution; Resonators; sensor; Spectra; Phase shift; Eigenmode; Line widths; Nanoelectromechanical device; Numerical method; Background noise; Spectral line shift; Vibrational modes; Analytical method; Bending; Mass measurement; Diffusion coefficient; Cumulant; Nanomechanical resonator
• ISSN: 0953-8984; 1361-648X; 1361-648X
• DOI: 10.1088/0953-8984/24/47/475301

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).