New Limit on the Permanent Electric Dipole Moment of ${}^{129}$Xe using ${}^3$He Comagnetometry and SQUID Detection

Abstract

We report results of a new technique to measure the electric dipole moment of ${}^{129}$Xe with ${}^3$He comagnetometry. Both species are polarized using spin-exchange optical pumping, transferred to a measurement cell, and transported into a magnetically shielded room, where SQUID magnetometers detect free precession in applied electric and magnetic fields. The result from a one week measurement campaign in 2017 and a 2.5 week campaign in 2018, combined with detailed study of systematic effects, is $d_A{(}^{129}\mathrm{Xe})=(1.4\pm 6.6_{\mathrm{stat}}\pm 2.0_{\mathrm{syst}})\times 10^{-28}e\mathrm{cm}$. This corresponds to an upper limit of $|d_A{(}^{129}\mathrm{Xe})|<1.4\times 10^{-27}e\mathrm{cm}(95\%\mathrm{CL})$, a factor of five more sensitive than the limit set in 2001.

To be published in Physical Review Letters. arXiv admin note: substantial text overlap with arXiv:1902.02864