Knowledge Bank

Molecules can be advantageous for the search for the electron electric dipole moment (eEDM) due to the large effective electric field experienced by a bound, unpaired electron. Furthermore, the closely-spaced states of opposite parity make the molecules easy to polarize in the lab frame. The JILA eEDM experiment currently uses HfF$+$ molecules in an ion trap to achieve long coherence times to reduce systematics. When an electric field is applied the eEDM signal is proportional to the shift in energy splitting between two Zeeman levels in a low-lying, metastable $3\Delta 1$ state. We have previously shown efficient preparation of trapped HfF$+$ molecules in the rovibronic ground state, $X1\Sigma +(v=0,J=0)$. Here, we demonstrate coherent transfer of population from the ground state to the $a3\Delta 1(v=0,J=1)$ state through an intermediate $3\Pi 0+$ state and efficient state read-out using photodissociation. In addition, we have begun to take spectroscopy data of the hyperfine and Zeeman structure of the eEDM science state in the presence of a rotating bias electric field and a magnetic field.