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 Micro/Nano-electromechanics |
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| Micro/Nano-nonlinear mechanics |
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Generic Rotating-Frame-Based Approach to Chaos Generation in Nonlinear Micro- and Nanoelectromechanical System Resonators S. Houri, M. Asano, H. Yamaguchi, N. Yoshimura, Y. Koike, and L. Minati, Phys. Rev. Lett. 125, 174301 (2020) |
| This Letter provides a low-power method for chaos generation that is generally applicable to nonlinear micro- and nanoelectromechanical systems (MNEMS) resonators. The approach taken is independent of the material, scale, design, and actuation of the device in question; it simply assumes a good quality factor and a Duffing type nonlinearity, features that are commonplace to MNEMS resonators. The approach models the rotating-frame dynamics to analytically constrain the parameter space required for chaos generation. By leveraging these common properties of MNEMS devices, a period-doubling route to chaos is generated using smaller forcing than typically reported in the literature. |  |
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Demonstration of Multiple Internal Resonances in a Microelectromechanical Self-Sustained Oscillator S. Houri, D. Hatanaka, M. Asano, and H. Yamaguchi, Phys. Rev. Applied 13, 014049 (2020) |
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We investigate the dynamics of a microelectromechanical self-sustained oscillator supporting multiple resonating and interacting modes. In particular, the interaction of the first four flexural modes along with the first torsional mode are studied, whereby 1:2, 1:3, and 2:1 internal resonances occur. Even and odd modes are induced to couple by breaking the longitudinal symmetry of the structure. Self-oscillations are induced in the second flexural mode via a gain-feedback loop; thereafter its frequency is pulled into a commensurate frequency ratio with the other modes, enabling the oscillator to act as a driver or pump for four modes simultaneously. |
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Optically probing Schwinger angular momenta in a micromechanical resonator M. Asano, R. Ohta, T. Aihara, T. Tsuchizawa, H. Okamoto, and H. Yamguchi, Phys. Rev. A 100, 053801 (2019) |
| We report an observation of phononic Schwinger angular momenta, which fully represent two-mode states in a micromechanical resonator. This observation is based on simultaneous optical detection of the mechanical response at the sum and difference frequency of the two mechanical modes. A postselection process for the measured signals allows us to extract a component of phononic Schwinger angular momenta. This postselection scheme with the nonlinear measurement enables us to conditionally prepare two-mode states, which shows a noise reduction along a cross-phase quadrature and a finite correlation, from a randomly excited (uncorrelated) state. The phononic Schwinger angular momenta could be extended to high-dimensional symmetry [e.g., SU(N) group] for studying multipartite correlations in nonequilibrium dynamics with macroscopic objects. |  |