Demonstration of an Electron Electric Dipole Moment Experiment Using Electric-Field Quantization in a Cesium Cold Atom Fountain

A Cs fountain electron electric dipole moment (EDM) experiment using electric-field quantization is demonstrated. With magnetic fields reduced to $\le$ 200 pT, the electric field lifts the degeneracy between hyperfine $|m_F|$ levels and, along with the fountain geometry, suppresses systematics from motional magnetic fields. Transitions are induced and the atoms polarized and analyzed in field-free regions. Our results suggest that a fountain experiment can detect (or rule out) an electron EDM far smaller than the present experimental limits.