Constraining the spin-gravity coupling effects to the $10^{-10}$-level with dual-species atom interferometers

Abstract

Spin is one fundamental property of microscopic particles. A lot of theoretical work has postulated the possible coupling between spin and gravitation, which could result in the violation of equivalence principle. In our recent joint mass-and-energy test of the weak equivalence principle with a 10-meter ${}^{85}$Rb-${}^{87}$Rb dual-species atom interferometer, the E$\ddot{\mathrm{o}}$tv$\ddot{\mathrm{o}}$s parameters of four ${}^{85}$Rb-${}^{87}$Rb combinations with specific atomic spin states were measured to the $10^{-10}$-level (\textit{L. Zhou et al., Phys. Rev. A 104, 022822}). Here these experimental results are used to constrain the postulated spin-gravity coupling effects. The bounds on the spin-independent and spin-dependent anomalous passive gravitational mass tensors in L$\ddot{\mathrm{a}}$mmerzahl's model are set to the $10^{-10}$-level, which improves existing bounds by three orders of magnitude. The constraints to the spin-independent electron- and proton-gravity coupling parameters in the gravitational standard-model extension are set to the $10^{-6}\mathrm{GeV}$-level.

9 pages, 2 figures