Resonant nonlinear response of a nanomechanical system with broken symmetry
Resonant nonlinear response of a nanomechanical system with broken symmetry
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DOI：
10.1103/physrevb.104.155434
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发表时间：
2021-10-27
影响因子：
3.7
通讯作者：
Weig, E. M.
中科院分区：
文献类型：
--
作者：
Ochs, J. S.;Rastelli, G.;Weig, E. M.
我们研究了一个弱阻尼振动模式的纳米弦谐振器的响应，一个中等强度的共振驱动力。由于实验的几何形状，所研究的弯曲振动缺乏反演对称性。正如我们所示，这导致了一个非平凡的依赖力参数的振动振幅。对于相对较弱的力，响应具有熟悉的Duffing形式，但对于稍微较强的力，它变得明显不同。与此同时，出现了两倍于驱动频率的振动，这是对称性破缺的标志。它们的振幅和相位使我们能够建立三次非线性的潜在模式的机制负责这两个意见。所发展的理论超越了标准的行波近似。它定量地描述了实验，并允许我们确定的非线性参数。
We study the response of a weakly damped vibrational mode of a nanostring resonator to a moderately strong resonant driving force. Because of the geometry of the experiment, the studied flexural vibrations lack inversion symmetry. As we show, this leads to a nontrivial dependence of the vibration amplitude on the force parameters. For a comparatively weak force, the response has the familiar Duffing form, but for a somewhat stronger force, it becomes significantly different. Concurrently there emerge vibrations at twice the drive frequency, a signature of the broken symmetry. Their amplitude and phase allow us to establish the cubic nonlinearity of the potential of the mode as the mechanism responsible for both observations. The developed theory goes beyond the standard rotating-wave approximation. It quantitatively describes the experiment and allows us to determine the nonlinearity parameters.