Real-time monitoring of minute quantities of charge plays an important role in quantum-physics research and electrical measurements within modern high-end scientific instruments. High-precision charge detection approaching the single-electron level at room temperature in analog or digital electronics is limited due to the considerable thermal noise. Herein, we propose a method of charge measurement with a resolution of 0.17 e/√Hz at room temperature by resonant electrometry based on tracking the quasidigital frequency output of a highly force-sensitive oscillator. Real-time charge monitoring by 67 electrons per step is performed. We demonstrate a charge prebiased scheme for physically manipulating the quadratic nature of charge sensing of the oscillator into parabolic and linear forms with dramatic improvements in metrics such as sensitivity and resolution. Theoretical models for describing the underlying physics of both the charge measurement and resolution amplification schemes are established and validated. Due to the high quality factor of the resonator, the theoretical limit for the charge-input referred noise of the electrometer induced by thermomechanical noise is estimated in the order of ${10}^{-4}\mathrm{e}$/√Hz. This study also provides insights of resonant sensing applied to the next generation of electrometers and associated instrumentation systems.

中文翻译：

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利用微机械振荡器的超灵敏共振电化学法

微小电荷的实时监控在现代高端科学仪器中的量子物理学研究和电学测量中发挥着重要作用。由于相当大的热噪声，模拟或数字电子产品中的室温下接近单电子水平的高精度电荷检测受到限制。本文中，我们基于跟踪高度力敏振荡器的准数字频率输出，提出了一种通过共振电法在室温下测量分辨率为0.17 e /√Hz的电荷的方法。每步通过67个电子进行实时电荷监控。我们展示了一种电荷预偏置方案，可通过物理方式将振荡器的电荷感测的二次性质操纵为抛物线和线性形式，并在灵敏度和分辨率等指标上取得了显着改善。建立并验证了用于描述电荷测量和分辨率放大方案的基本物理原理的理论模型。由于谐振器的品质因数高，因此热机械噪声引起的静电计的电荷输入参考噪声的理论极限按以下顺序估算：${10}^{-4}\mathrm{Ë}$/√Hz。这项研究还提供了应用于下一代静电计和相关仪表系统的共振感应的见解。