First Measurement of the Atomic Electric Dipole Moment of ²²⁵Ra

This is the authors' abstract. We don't add key points for this paper.

The radioactive radium-225 (²²⁵Ra) atom is a favorable case to search for a permanent electric dipole moment (EDM). Due to its strong nuclear octupole deformation and large atomic mass, ²²⁵Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of ²²⁵Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic EDM, reaching an upper limit of $|$$d$($²²⁵$Ra)$|$ $