In-orbit Test of the Weak Equivalence Principle with Atom Interferometry
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.
Cite
@article{arxiv.2603.22981,
title = {In-orbit Test of the Weak Equivalence Principle with Atom Interferometry},
author = {Dan-Fang Zhang and Jing-Ting Li and Wen-Zhang Wang and Wei-Hao Xu and Jia-Yi Wei and Xiao Li and Yi-Bo Wang and Dong-Feng Gao and Jia-Qi Zhong and Biao Tang and Lin Zhou and Run-Bing Li and Huan-Yao Sun and Qun-Feng Chen and Lei Qin and Mei-zhen An and Zong-Feng Li and Shu-Quan Wang and Xiao-Xiao Guo and Yao Tian and Xi-He Yu and Hong-En Zhong and Xi Chen and Jin Wang and Ming-Sheng Zhan},
journal= {arXiv preprint arXiv:2603.22981},
year = {2026}
}
Comments
22 pages,6 figures