In-orbit Test of the Weak Equivalence Principle with Atom Interferometry

TL;DR

This paper reports the first in-orbit quantum test of the Weak Equivalence Principle using a dual-species atom interferometer aboard the China Space Station, achieving unprecedented measurement precision and advancing space-based quantum sensors.

Contribution

It demonstrates a novel in-orbit atom interferometry method for testing the WEP with significantly improved accuracy over previous ground-based experiments.

Findings

Test uncertainty of 2.8×10⁻⁸ from 280 days of data

Achieved a WEP test result of (-3.1±4.6)×10⁻⁷

Improved measurement precision by three orders of magnitude

Abstract

The Weak Equivalence Principle (WEP) is a central pillar of general relativity. Its precise test with quantum systems in space offers a unique window onto new physics. Here we report the first in-orbit quantum test of the WEP. A dual-species (85Rb/87Rb) atom interferometer is realized aboard the China Space Station. Methods of platform motion suppression, fluorescence detection switching, and two-photon detuning switching are developed to eliminate phase noise and improve measurement accuracy. A test uncertainty of 2.8*10-8 is obtained from 280 days of WEP test data, and a test result of (-3.1+/-4.6)*10-7 is achieved after error estimation. This improves prior atom-interferometric WEP tests in microgravity by three orders of magnitude. This work paves the way for space-borne quantum inertial sensors and their application to future fundamental physics in space.