Laser-induced fluorescence studies of HfF+ produced by autoionization

TL;DR

This study uses laser-induced fluorescence to analyze autoionization of Rydberg HfF molecules, demonstrating selective ion state creation and providing insights for electron EDM experiments.

Contribution

It characterizes a specific Rydberg vibronic band of HfF and models autoionization, enabling targeted ion state preparation for fundamental physics research.

Findings

30% ion yield in a specific |J+,M+> state

Rydberg molecules decay into few ion rotational states

Autoionization preserves molecular orientation

Abstract

Autoionization of Rydberg states of HfF, prepared using the optical-optical double resonance (OODR) technique, holds promise to create HfF+ in a particular Zeeman level of a rovibronic state for an electron electric dipole moment (eEDM) search. We characterize a vibronic band of Rydberg HfF at 54 cm-1 above the lowest ionization threshold and directly probe the state of the ions formed from this vibronic band by performing laser-induced fluorescence (LIF) on the ions. The Rydberg HfF molecules show a propensity to decay into only a few ion rotational states of a given parity and are found to preserve their orientation qualitatively upon autoionization. We show empirically that we can create 30% of the total ion yield in a particular |J+,M+> state and present a simplified model describing autoionization from a given Rydberg state that assumes no angular dynamics.