Development of Levitated, Macroscopically Delocalized Atom Interferometers for a New Measurement of Newton's Constant G

Quantum mechanical measurements of G based on atom interferometric gravity gradiometers are an important complement to classical measurements, as they have a different set of systematic errors. Owing to recent advances in atomic physics, it appears that previously dominant systematic errors in atom interferometric G measurements can be highly suppressed. In the next generation of atomic G measurements, proof mass density inhomogeneities are expected to be a limiting systematic effect. This proposal aims to develop and demonstrate techniques to improve the sensitivity of atom interferometric gravity gradiometers by a factor of 100 over the current state-of-the-art. This level of sensitivity would open a path for improved atom interferometric measurements of G by allowing such measurements to trade off higher proof mass density for better density homogeneity by using single-crystal silicon, while maintaining sufficient statistical resolution in the measurement.