Test of Equivalence Principle at10−8Level by a Dual-Species Double-Diffraction Raman Atom Interferometer

Abstract

We report an improved test of the weak equivalence principle by using a simultaneous $^{85}\mathrm{Rb}\text{\ensuremath{-}}^{87}\mathrm{Rb}$ dual-species atom interferometer. We propose and implement a four-wave double-diffraction Raman transition scheme for the interferometer, and demonstrate its ability in suppressing common-mode phase noise of Raman lasers after their frequencies and intensity ratios are optimized. The statistical uncertainty of the experimental data for E\"otv\"os parameter $\ensuremath{\eta}$ is $0.8\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}8}$ at 3200 s. With various systematic errors corrected, the final value is $\ensuremath{\eta}=(2.8\ifmmode\pm\else\textpm\fi{}3.0)\ifmmode\times\else\texttimes\fi{}1{0}^{\ensuremath{-}8}$. The major uncertainty is attributed to the Coriolis effect.