Quantum degenerate mixture of ytterbium and lithium atoms

Abstract

We have produced a quantum degenerate mixture of fermionic alkali-metal 6 Li and bosonic spin-singlet 174 Yb gases. This was achieved using sympathetic cooling of lithium atoms by evaporatively cooled ytterbium atoms in a far-off-resonant optical dipole trap. We observe the coexistence of Bose-condensed (T /T c 0.8) 174 Yb with 2.3 × 10 4 atoms and Fermi degenerate (T /T F 0.3) 6 Li with 1.2 × 10 4 atoms. Quasipure Bose-Einstein condensates of up to 3 × 10 4 174 Yb atoms can be produced in single-species experiments. Our results mark a significant step toward studies of few-and many-body physics with mixtures of alkali-metal and alkaline-earthmetal-like atoms, and for the production of paramagnetic polar molecules in the quantum regime. Our methods also establish a convenient scheme for producing quantum degenerate ytterbium atoms in a 1064 nm optical dipole trap.

Prospects of forming ultracold molecules in2Σstates by magnetoassociation of alkali-metal atoms with Yb

“…There is now great interest in the formation of cold molecules that have both electric and magnetic dipole moments [19][20][21][22][23][24]. Such molecules offer additional possibilities for manipulation, trapping, and control because they can be influenced by both electric and magnetic fields.…”

Ground- and excited-state properties of the polar and paramagnetic RbSr molecule: A comparative study

“…That might allow the experimentalist to modify the scattering length in the ultracold mixture of Rb and Sr and control the behaviour of quantum gas of such atoms. It is worth mentioning that several other similar species are subject to intense ongoing research, like YbLi [30][31][32][33][34] and YbRb [35][36][37].…”

Interspecies thermalization in an ultracold mixture of Cs and Yb in an optical trap

“…Although the large majority of work on ultracold molecules has focused on bi-alkali systems, there is burgeoning interest in pairing alkali-metal atoms with divalent atoms such as Yb [40][41][42][43][44][45] or Sr [46]. The heteronuclear 2 Σ molecules formed in these systems have both an electric and a magnetic dipole moment in the ground electronic state.…”

“…These ultracold molecules have a wealth of applications, such as tests of fundamental physics [27][28][29], realization of novel phase transitions [30][31][32], and the study of ultracold chemistry [33,34]. In addition, the long-range dipole-dipole interactions present between pairs of polar molecules make them useful in the study of dipolar quantum matter [35,36] and ultracold molecules confined in an optical lattice can simulate a variety of condensedmatter systems [37][38][39].Although the large majority of work on ultracold molecules has focused on bi-alkali systems, there is burgeoning interest in pairing alkali-metal atoms with divalent atoms such as Yb [40][41][42][43][44][45] or Sr [46]. The heteronuclear 2 Σ molecules formed in these systems have both an electric and a magnetic dipole moment in the ground electronic state.…”