Relativistic Coupled-Cluster Study of Diatomic Metal-Alkali Molecules for Electron Electric Dipole Moment Searches

TL;DR

This study uses relativistic coupled-cluster calculations to evaluate electric fields and interaction coefficients in diatomic metal-alkali molecules, aiding electron electric dipole moment searches with ultracold molecules.

Contribution

It provides detailed relativistic calculations of molecular properties for SrA and HgA molecules, highlighting basis set effects and comparing with fluoride and hydride analogs.

Findings

Effective electric fields (Eeff) and S-PS coefficients (Ws) calculated at multiple levels.

Analysis of the ratio Ws/Eeff at different theoretical levels.

Comparison of molecular properties with fluoride and hydride counterparts.

Abstract

Recent improvements in experimental techniques for preparing ultracold molecules that contain alkali atoms (e.g., Li, Na, and K) have been reported. Based on these advances in ultracold molecules, new searches for the electric dipole moment of the electron and the scalar-pseudoscalar interaction can be proposed on such systems. We calculate the effective electric fields (Eeff) and the S-PS coefficients (Ws) of SrA and HgA (A = Li, Na, and K) molecules at the Dirac-Fock (DF) and the relativistic coupled cluster (RCC) levels. We elaborate on the following points: i) Basis set dependence of the molecular properties in HgA, ii) Analysis of Eeff and Ws in SrA and HgA, and comparison with their fluoride and hydride counterparts, iii) Ratio of Ws to Eeff (Ws/Eeff) at the DF and the correlation RCC levels of theory.