Quantum Degenerate Gases of Yb

Abstract

The initial steps for the efficient production of ultracold molecules relies upon the preparation of an ultracold mixture of the constituent atoms, where both species are confined in a conservative trap. The numerous Yb isotopes that are capable of being cooled to quantum degeneracy [16, 17, 47, 48, 50, 51] make Yb an attractive element to work with in this regard. Quantum degeneracy in ultracold gases is normally achieved by evaporatively cooling the sample in a conservative trap. Bosonic Yb isotopes do not have a magnetic moment in the ground state and fermionic Yb isotopes only have a weak magnetic moment on the order of the nuclear magnetic moment, three orders of magnitude weaker than the Bohr magneton \(\mu _\mathrm{B}\). Therefore, magnetic traps of fermionic Yb isotopes would require extremely large gradients >T/cm. A more sensible solution is the confinement of Yb in an optical dipole trap (ODT). This allows the magnetic field to be tuned without effecting the trapping potential, which enables the search for CsYb Feshbach resonances and magnetoassociation of the mixture.