# The 27th International Conference on Atomic Physics

17-22 July 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

## Ultracold mixtures of Cr and Li atoms: theoretical prospects for controlled atomic collisions, LiCr molecule formation, and molecular precision measurements

20 Jul 2022, 17:00
1h 30m
Hart House (Hart House)

### Hart House

#### Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Structure and properties of atoms, ions, and molecules

### Description

We theoretically investigate interatomic interactions and ultracold collisions between chromium and lithium atoms. We use the coupled cluster and multireference configuration interaction methods to calculate the potential energy curves and the permanent and transition electric dipole moments for the quartet, sextet, and octet electronic states of the LiCr molecule correlated to the four lowest atomic dissociation limits. We find that the LiCr molecule in the $X\,^6\Sigma^+$ ground electronic state is strongly bound with the well depth of 8406(100)$\,$cm$^{-1}$ and has a large permanent electric dipole moment of 3.3$\,$D at an equilibrium distance of 4.87$\,$bohr, while the $a\,^8\Sigma^+$ first excited electronic states is weakly bound with the well depth of 565(18)$\,$cm$^{-1}$ and has a noticeable permanent electric dipole moment of $0.7\,$D at the equilibrium distance of 6.48$\,$bohr. We investigate the optical paths of forming deeply-bound LiCr molecules via photoassociation and stimulated Raman adiabatic passage. We propose precision measurements of the variation of electron-to-proton mass ratio using ultracold LiCr molecules. We predict the scattering lengths for the ultracold spin-polarized Cr+Li collisions (37$^{+29}_{-22}\,$bohr for $^{53}$Cr+$^6$Li) governed by the $a\,^8\Sigma^+$ electronic state without any adjustment to experimental data and in good agreement with recent experimental measurements. Finally, we calculate magnetically tunable Feshbach resonances for ultracold $^{52}$Cr+$^6$Li and $^{53}$Cr+$^6$Li collisions and assess prospects for magnetoassociation into polar and highly magnetic LiCr molecules. Present theoretical results may guide ongoing experimental studies on ultracold strongly-interacting mass-imbalanced Fermi-Fermi Li+Cr mixtures and LiCr molecules.

Presenter name Klaudia Zaremba-Kopczyk

### Primary authors

Klaudia Zaremba-Kopczyk (Faculty of Physics, University of Warsaw) Marcin Gronowski (Institute of Physical Chemistry, Polish Academy of Sciences) Michal Tomza (Faculty of Physics, University of Warsaw)

### Presentation Materials

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