Hypermetallic polar molecules for precision measurements

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.

Determination of CaOH and CaOCH3 vibrational branching ratios for direct laser cooling and trapping

“…Recently, quantum state controlled synthesis of BaOCa + has been demonstrated [83] and theoretical work on neutral MOM (same metal) molecules has been performed motivated by the potential to search for fine structure constant α variation [84]. Neutral polyatomic molecules functionalized with optical cycling centers like Ca or Sr could also enable interesting applications in quantum sciences [85,86].…”

Toward Ultracold Organic Chemistry: Prospects of Laser Cooling Large Organic Molecules

“…47,48 A scope of possible applications in QIS, precision measurements and ultracold chemistry can be expanded by incorporating multiple cycling centers into a single molecule. [33][34][35] In this context, benzene offers a versatile framework that can host multiple cycling centers with various geometrical configurations. For example, CaBzCa hosts two cycling centers and may exist in three configurations (para, meta, and ortho) with varied separation length between the two centers ( Figure 7).…”

“…The ability to exploit highly localized excitation for optical cycling of such triatomic molecules as CaOH, SrOH, and YbOH spur an interest in studying optical cycling schemes in more complex polyatomic molecules. 27,28,[32][33][34][35] Using CaOH as example, the localization of the unpaired electron is facilitated by the locally ionic character of the Ca-O bond, and thus various saturated and unsaturated hydrocarbon groups can follow O atom without significantly deteriorating the FCFs. 28 A recent demonstration of laser cooling of CaOCH 3 proves this concept and suggests that optical cycling and laser cooling of large polyatomic molecules can be as efficient as for much simpler linear species.…”

Towards Ultracold Organic Chemistry: Prospects of Laser Cooling Large Organic Molecules

“…47,48 A scope of possible applications in QIS, precision measurements and ultracold chemistry can be expanded by incorporating multiple cycling centers into a single molecule. [33][34][35] In this context, benzene offers a versatile framework that can host multiple cycling centers with various geometrical configurations. For example, CaBzCa hosts two cycling centers and may exist in three configurations (para, meta, and ortho) with varied separation length between the two centers (Figure 7).…”

“…The ability to exploit highly localized excitation for optical cycling of such triatomic molecules as CaOH, SrOH, and YbOH spur an interest in studying optical cycling schemes in more complex polyatomic molecules. 27,28,[32][33][34][35] Using CaOH as example, the localization of the unpaired electron is facilitated by the locally ionic character of the Ca-O bond, and thus various saturated and unsaturated hydrocarbon groups can follow O atom without significantly deteriorating the FCFs. 28 A recent demonstration of laser cooling of CaOCH 3 proves this concept and suggests that optical cycling and laser cooling of large polyatomic molecules can be as efficient as for much simpler linear species.…”