Determination of the Newtonian Gravitational Constant Using Atom Interferometry

TLDR

This method is intriguing because it explores gravity with a quantum system, offering potential sensitivity. The study presents a new measurement of the Newtonian gravitational constant G using cold‑atom interferometry. The experiment uses freely falling laser‑cooled rubidium atoms in a gravity gradiometer to probe the field from nearby source masses. We report G = 6.667 × 10⁻¹¹ m³ kg⁻¹ s⁻² with statistical uncertainty ±0.011 × 10⁻¹¹ and systematic ±0.003 × 10⁻¹¹, and demonstrate long‑term stability and signal‑to‑noise that suggest potential accuracy below 100 ppm.

Abstract

We present a new measurement of the Newtonian gravitational constant G based on cold-atom interferometry. Freely falling samples of laser-cooled rubidium atoms are used in a gravity gradiometer to probe the field generated by nearby source masses. In addition to its potential sensitivity, this method is intriguing as gravity is explored by a quantum system. We report a value of G = 6.667 x 10(-11) m(3) kg(-1) s(-2), estimating a statistical uncertainty of +/-0.011 x 10(-11) m(3) kg(-1) s(-2) and a systematic uncertainty of +/-0.003 x 10(-11) m(3) kg(-1) s(-2). The long-term stability of the instrument and the signal-to-noise ratio demonstrated here open interesting perspectives for pushing the measurement accuracy below the 100 ppm level.