Atom Interferometer Measurement of the Newtonian Constant of Gravity

TLDR

The possibility that unknown systematic errors still exist in traditional measurements makes it important to measure G with independent methods. We measured the Newtonian constant of gravity, G, using a gravity gradiometer based on atom interferometry that records the differential acceleration of two laser‑cooled Cs atom samples while a well‑characterized Pb mass is displaced to create a known gravitational field gradient. We report G = 6.693 × 10⁻¹¹ m³ kg⁻¹ s⁻² with a standard error of ±0.027 × 10⁻¹¹ and a systematic error of ±0.021 × 10⁻¹¹.

Abstract

We measured the Newtonian constant of gravity, G , using a gravity gradiometer based on atom interferometry. The gradiometer measures the differential acceleration of two samples of laser-cooled Cs atoms. The change in gravitational field along one dimension is measured when a well-characterized Pb mass is displaced. Here, we report a value of G = 6.693 × 10 –11 cubic meters per kilogram second squared, with a standard error of the mean of ±0.027 × 10 –11 and a systematic error of ±0.021 × 10 –11 cubic meters per kilogram second squared. The possibility that unknown systematic errors still exist in traditional measurements makes it important to measure G with independent methods.