Ultracold interactions and collisions in quantum mixtures of highly magnetic atoms and alkali-metal atoms

We study ultracold interactions and collisions in quantum mixtures of highly magnetic $S$-state atoms, Cr ($^7S_3$) and Eu ($^8S_{7/2}$), and alkali-metal atoms. We investigate magnetically tunable Feshbach resonances between ultracold europium atoms and between europium and alkali-metal atoms using multichannel quantum scattering calculations [1]. The calculations are carried out for representative systems of $^{153}$Eu+$^7$Li and $^{153}$Eu+$^{87}$Rb, as well as for homonuclear $^{153}$Eu+$^{153}$Eu and heteronuclear $^{153}$Eu+$^{151}$Eu systems. We analyze the prospects for the control of scattering properties and magnetoassociation into ultracold polar and paramagnetic molecules. We show that favorable resonances can be expected at experimentally feasible magnetic-field strengths below 1000 G for all investigated atomic combinations. For the mixtures of chromium with alkali-metal atoms, we consider a prototype system of $^{53}$Cr+$^6$Li. We calculate the potential energy curves for the CrLi molecule both in ground and excited states, investigate magnetic Feshbach resonances, prospects for photoassociation and application of CrLi molecules to precision measurements.\\ [1] K. Zaremba-Kopczyk, P. S. \.{Z}uchowski, M. Tomza, Phys. Rev. A 98, 032704 (2018).