State-specific detection of trapped HfF+ by photodissociation

Abstract

We use (1+1′) resonance-enhanced multiphoton photodissociation (REMPD) to detect the population in individual rovibronic states of trapped HfF+ with a single-shot absolute efficiency of 18%, which is over 200 times better than that obtained with fluorescence detection. The first photon excites a specific rotational level to an intermediate vibronic band at 35000–36500cm−1, and the second photon, at 37594cm−1 (266nm), dissociates HfF+ into Hf+ and F. Mass-resolved time-of-flight ion detection then yields the number of state-selectively dissociated ions. Using this method, we observe rotational-state heating of trapped HfF+ ions from collisions with neutral Ar atoms. Furthermore, we measure the lifetime of the 3Δ1v=0,J=1 state to be 2.1(2)s. This state will be used for a search for a permanent electric dipole moment of the electron.