Dual matter-wave inertial sensors in weightlessness

TLDR

Cold‑atom interferometers promise high‑precision inertial sensing and fundamental physics, yet Earth’s limited free‑fall time restricts their sensitivity; space offers longer interrogation times and unprecedented performance, motivating current missions to deploy matter‑wave inertial sensors. We aim to demonstrate the first onboard operation of simultaneous 87Rb–39K interferometers in a weightless environment. We achieve this by operating the dual interferometers during parabolic flight, confronting vibration levels of 10⁻² g/√Hz, acceleration ranges up to 1.8 g, and rotation rates of 5 deg/s. The dual sensor measured the Eötvös parameter with uncertainties of 1.1 × 10⁻³ in standard gravity and 3.0 × 10⁻⁴ in microgravity, constituting the first equivalence‑principle test with quantum sensors in a free‑fall vehicle and demonstrating applicability to inertial navigation and future satellite missions.

Abstract

Quantum technology based on cold-atom interferometers is showing great promise for fields such as inertial sensing and fundamental physics. However, the best precision achievable on Earth is limited by the free-fall time of the atoms, and their full potential can only be realized in Space where interrogation times of many seconds will lead to unprecedented sensitivity. Various mission scenarios are presently being pursued which plan to implement matter-wave inertial sensors. Toward this goal, we realize the first onboard operation of simultaneous $^{87}$Rb $-$ $^{39}$K interferometers in the weightless environment produced during parabolic flight. The large vibration levels ($10^{-2}~g/\sqrt{\rm Hz}$), acceleration range ($0-1.8~g$) and rotation rates ($5$ deg/s) during flight present significant challenges. We demonstrate the capability of our dual-quantum sensor by measuring the E\"{o}tv\"{o}s parameter with systematic-limited uncertainties of $1.1 \times 10^{-3}$ and $3.0 \times 10^{-4}$ during standard- and micro-gravity, respectively. This constitutes the first test of the equivalence principle in a free-falling vehicle with quantum sensors. Our results are applicable to inertial navigation, and can be extended to the trajectory of a satellite for future Space missions.