Centre for Engineered Quantum Systems, Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109, Australia.
Sci Rep. 2016 Nov 21;6:37495. doi: 10.1038/srep37495.
Precision measurements of gravity can provide tests of fundamental physics and are of broad practical interest for metrology. We propose a scheme for absolute gravimetry using a quantum magnetomechanical system consisting of a magnetically trapped superconducting resonator whose motion is controlled and measured by a nearby RF-SQUID or flux qubit. By driving the mechanical massive resonator to be in a macroscopic superposition of two different heights our we predict that our interferometry protocol could, subject to systematic errors, achieve a gravimetric sensitivity of Δg/g ~ 2.2 × 10 Hz, with a spatial resolution of a few nanometres. This sensitivity and spatial resolution exceeds the precision of current state of the art atom-interferometric and corner-cube gravimeters by more than an order of magnitude, and unlike classical superconducting interferometers produces an absolute rather than relative measurement of gravity. In addition, our scheme takes measurements at ~10 kHz, a region where the ambient vibrational noise spectrum is heavily suppressed compared the ~10 Hz region relevant for current cold atom gravimeters.
精确测量重力可以为基础物理提供检验，并在计量学方面具有广泛的实际意义。我们提出了一种使用量子磁力学系统进行绝对重力测量的方案，该系统由一个磁囚禁超导谐振器组成，其运动由附近的射频超导量子干涉仪（RF-SQUID）或磁通量子比特控制和测量。通过驱动机械质量谐振器处于两个不同高度的宏观叠加状态，我们预测我们的干涉测量协议可以在系统误差的情况下，实现重力灵敏度Δg/g≈2.2×10^-11 Hz，空间分辨率为几个纳米。与当前最先进的原子干涉仪和角反射器重力计相比，这种灵敏度和空间分辨率超过了一个数量级，并且与传统超导干涉仪不同，它产生的是重力的绝对测量，而不是相对测量。此外，我们的方案在10 kHz 的频率下进行测量，在这个频率范围内，环境振动噪声谱相对于当前冷原子重力计相关的10 Hz 频率范围受到严重抑制。
