# Hypermetallic Polar Molecules for Precision Measurements

## TL;DR

This paper explores hypermetallic molecules containing multiple metal centers, analyzing their potential for laser cooling and precision measurements, thereby expanding the range of molecules suitable for quantum control and fundamental physics experiments.

## Contribution

It introduces a detailed analysis of YbCCCa and YbCCAl molecules, demonstrating their feasibility for laser cooling and precision measurement applications, which was previously challenging with many metal centers.

## Key findings

- YbCCCa and YbCCAl are linear molecules with metal-centered valence electrons.
- These molecules exhibit complex hybridization and spin structures relevant to photon cycling.
- Hypermetallic molecules could enable laser cooling of otherwise difficult metal species.

## Abstract

Laser cooling is a powerful method to control molecules for applications in precision measurement, as well as quantum information, many-body physics, and fundamental chemistry. However, many optically-active metal centers in valence states which are promising for these applications, especially precision measurement, are difficult to laser cool. In order to extend the control afforded by laser cooling to a wider array of promising atoms, we consider the use of small, hypermetallic molecules that contain multiple metal centers. We provide a detailed analysis of YbCCCa and YbCCAl as prototypical examples with different spin multiplicities, and consider their feasibility for precision measurements making use of the heavy Yb atom. We find that these molecules are linear and feature metal-centered valence electrons, and study the complex hybridization and spin structures that are relevant to photon cycling and laser cooling. Our findings suggest that this hypermetallic approach may be a versatile tool for experimental control of metal species that do not otherwise efficiently cycle photons, and could present a new polyatomic platform for state-of-the-art precision measurements.