Abstract

The electromechanical coupling in the nanomechanical detection experiment is important as people forever pursue the higher sensitivity. In this work, we have studied theoretically the electromechanical coupling effect on the sensitivity of nanomechanical motion with the mixing current detection method under monostable and bistable regime, respectively. To obtain the sensitivity, the response function, the shot noise and the backaction noise with the coupling in the nanomechanical system consists of the oscillator coupled to a quantum dot are present. It is found that for the monostable state, the higher coupling means higher sensitivity. Both the contributions of shot noise and the backaction noise to the sensitivity are the decreasing function of the coupling. Once the system enters the bistability regime, the telegraph noise dominates instead of the resonance frequency noise, that due to the electron hopping in the bistable regime contributes more noise for the detection, its value is 3 orders of magnitude larger than the contribution of shot noise. As a result, one could find that there is a optimal value of the coupling corresponding to the phase transition point where the sensitivity is the best. Our results provide the pioneer and useful approach for the detection experiment.

Graphic abstract

中文翻译：

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机电耦合效应在纳米机械运动检测中的应用

摘要

纳米机械检测实验中的机电耦合非常重要，因为人们永远追求更高的灵敏度。在这项工作中，我们从理论上研究了在单稳态和双稳态条件下用混合电流检测方法对纳米机械运动灵敏度的机电耦合效应。为了获得灵敏度，存在由耦合到量子点的振荡器组成的纳米机械系统中的耦合的响应函数，散粒噪声和背作用噪声。发现对于单稳态，较高的耦合意味着较高的灵敏度。散粒噪声和后向噪声对灵敏度的贡献都是耦合的递减函数。系统进入双稳态之后，电报噪声而不是谐振频率噪声占主导地位，这是由于双稳态状态下的电子跳跃为检测贡献了更多的噪声，其值比散粒噪声的贡献大3个数量级。结果，可以发现存在与灵敏度最佳的相变点相对应的耦合的最佳值。我们的结果为检测实验提供了开创性和有用的方法。

图形摘要