Spectroscopy on the eEDM-sensitive states of ThF${}^{+}$

Abstract

An excellent candidate molecule for the measurement of the electron's electric dipole moment (eEDM) is thorium monofluoride (ThF${}^{+}$) because the eEDM-sensitive state, ${}^3\hat{I}{”}_1$, is the electronic ground state, and thus is immune to decoherence from spontaneous decay. We perform spectroscopy on $X{}^3\hat{I}{”}_1$ to extract three spectroscopic constants crucial to the eEDM experiment: the hyperfine coupling constant, the molecular frame electric dipole moment, and the magnetic $g$-factor. To understand the impact of thermal blackbody radiation on the vibrational ground state, we study the lifetime of the first excited vibrational manifold of $X{}^3\hat{I}{”}_1$. We perform ab initio calculations, compare them to our results, and discuss prospects for using ThF${}^{+}$ in a new eEDM experiment at JILA.

9 pages, 8 figures