Ultracold mercury-alkali molecules for electron electric dipole moment searches

TL;DR

This paper proposes mercury-alkali diatomic molecules as promising candidates for electron EDM searches due to their large effective electric fields and feasibility of producing ultracold trapped samples, potentially enabling more sensitive experiments.

Contribution

It introduces a new family of ultracold mercury-alkali molecules and calculates their effective electric fields, highlighting their suitability for eEDM experiments.

Findings

Mercury-alkali molecules have large effective electric fields.

These molecules can be feasibly produced from ultracold atoms.

They are identified as favorable candidates for eEDM searches.

Abstract

Heavy polar diatomic molecules are the leading candidates in searches for the permanent electric dipole moment of the electron (eEDM). Next-generation eEDM search experiments ideally require extremely large coherence times, in large ensembles of trapped molecules that have a high sensitivity to the eEDM. We consider a family of molecules, mercury-alkali diatomics, that can be feasibly produced from ultracold atoms. We present calculations of the effective electric fields experienced by the electron in these molecules. The combination of reasonably large effective electric fields, and a straightforward path to obtaining trapped ultracold samples, lead us to identify these molecules as favorable candidates for eEDM search experiments.