Experimental realization of ultracold Yb-${}^7\mathrm{Li}$ mixtures in mixed dimensions

Abstract

We report on the experimental realization of ultracold ${}^{174}\mathrm{Yb}$-${}^7\mathrm{Li}$ (Boson-Boson) and ${}^{173}\mathrm{Yb}$-${}^7\mathrm{Li}$ (Fermion-Boson) mixtures. They are loaded into three dimensional (3D) or one dimensional (1D) optical lattices that are species-selectively deep for the heavy Ytterbium (Yb) and shallow for the light bosonic Lithium (Li) component, realizing novel mixed dimensional systems. In the 1D optical lattice the band structure of ${}^{173}\mathrm{Yb}$ is reconstructed in the presence of ${}^7\mathrm{Li}$. Spectroscopic measurements of the ${}^{174}\mathrm{Yb}$-${}^7\mathrm{Li}$ mixture in the 3D lattice give access to the ${}^{174}\mathrm{Yb}$ Mott-insulator structure. Ground state inter-species scattering lengths are determined to be $|a_{\mathrm{bg}}{(}^{174}\mathrm{Yb}$-${}^7\mathrm{Li})|=(1.11\pm 0.17)\mathrm{nm}$ and $|a_{\mathrm{bg}}{(}^{173}\mathrm{Yb}$-${}^7\mathrm{Li})|=(1.16\pm 0.18)\mathrm{nm}$. The formation and characterization of an ultracold ${}^{173}\mathrm{Yb}$-${}^7\mathrm{Li}$ mixture is a first step towards a possible realization of a topological $p_x+i{p}_y$ superfluid in this system.