Electric field dissociation of weakly bound molecular ions

TL;DR

This study provides a quantum mechanical analysis of how weakly bound molecular ions dissociate under external electric fields in Paul traps, confirming their survival and proposing a method for their detection.

Contribution

It offers the first full quantum study of molecular ion dissociation in time-dependent electric fields within Paul traps, supporting experimental observations and suggesting a new detection technique.

Findings

Weakly bound molecular ions survive in Paul traps, especially at high RF frequencies.

Applying an electric field ramp enables state-selective detection of these ions.

The results align with previous experimental findings on molecular ion stability.

Abstract

We present a full quantal study on the dissociation of a weakly bound molecular ion in the presence of an external time-dependent electric field. We focus on the dissociation dynamics of a molecular ion in a Paul trap relevant for atom-ion hybrid traps. Our results show that a weakly bound molecular ion survives in a Paul trap giving a theoretical ground to previous experimental findings [A. Kr\"ukow et al. Phys. Rev. Lett. 116, 193201 (2016) and A. Mohammadi et al. Phys. Rev. Research 3, 013196 (2021)]. In particular, we find that weakly bound molecular ions are more likely to survive in traps with large RF frequency. Similarly, we show that applying an electric field ramp is an efficient method to state-selectively detect weakly bound molecular ions, analogous to the well-known selective field ionization technique applied in Rydberg atoms, that it may also be used to detect these species in atom-ion hybrid traps.