The quantum limits of micromachined gravity sensors

微机械重力传感器的量子极限

• 批准号: 2127813
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2127813
• 关键词: quantum; limits; micromachined; gravity; sensors

"This project will investigate the ultimate performance achievable with a micromachined gravity sensor. The goal is to develop an existing 0.25 ng/rtHz silicon sensor, the highest resolution presently achieved by an inertial silicon sensor by some margin, and previously delivered to NASA as a Mars microseismometer, but with application to gravity sensing. Although MEMS technology is generally limited by thermodynamic noise, either in the electronics or the suspension, we have now pushed these limits low enough that it appears that quantum effects are setting the ultimate performance. The first stage of this project is to probe the limiting role that quantum mechanics is playing in these sensors. It is believed that surface states on the electrodes of our position transducer may be playing an important role. If so, microfabrication may be able to minimise the contribution through an engineered approach to dimensionally constraining these states. This work might suggest a way to minimise the "patch" effect, a problematic noise source for ultrahigh precision sensors.The MSc work will involve modelling using finite element analysis of the electron states, and in particular the effect of the variation of surface potentials on the measurement of capacitance and producing a first principles estimation of the noise floor. This modelling will be extended to consider different electrode geometries. With the fundamental limitations better quantified, the PhD can proceed to investigate design trades to optimise sensor geometries, and then to build and lab test these under a range of possible deployments. "

这个项目将研究微机械重力传感器可以达到的最终性能。目标是开发一种现有的0.25 ng/rthz硅传感器，这是目前惯性硅传感器达到的最高分辨率，在一定程度上是目前达到的最高分辨率，以前作为火星微地震计交付给NASA，但用于重力传感。尽管MEMS技术通常受到热力学噪声的限制，无论是在电子设备还是在悬架上，但我们现在已经将这些限制降低到足够低的程度，似乎量子效应正在设定终极性能。该项目的第一阶段是探索量子力学在这些传感器中所起的限制作用。我们认为，我们的位置传感器电极上的表面态可能起着重要作用。如果是这样的话，微制造或许能够通过一种工程化的方法来限制这些状态，从而将贡献降至最低。这项工作可能会提出一种将“贴片”效应降至最低的方法，这是超高精度传感器的一个有问题的噪声源。MSC的工作将涉及使用电子态的有限元分析进行建模，特别是表面电位变化对电容测量的影响，并产生噪声下限的第一性原理估计。该模型将扩展到考虑不同的电极几何形状。随着基本限制得到更好的量化，博士可以继续调查设计交易，以优化传感器几何结构，然后在一系列可能的部署下建立并进行实验室测试。“