Spectroscopic determination of magnetic-field-dependent interactions in an ultracold Yb(3P2)-Li mixture

Abstract

We present experimental results on the inelastic and elastic interspecies interactions between ytterbium (Yb) in the metastable 3 P2 state loaded into a deep optical lattice and spin polarized lithium (Li) in its ground state. Focusing on the mJ = 0 magnetic sublevel of Yb( 3 P2), bias magnetic fields between 20 G and 800 G are investigated and significantly enhanced inelastic collision rates with high magnetic fields are found. In addition, by direct spectroscopy of the Yb Mottinsulator immersed in the Li Fermi gas an upper boundary of the background scattering length of the Yb( 3 P2, mJ = 0)-Li( 2 S 1/2 , F = 1/2, mF = +1/2) system is estimated, revealing the absence of useful Feshbach resonances. These observations are qualitatively consistent with the theoretical calculations.

Feshbach resonances of large mass-imbalance Er-Li mixtures

“…Additionally, the present work reveals mixture lifetimes on the order of up to 1 s even at resonance. This is, e.g., about two orders of magnitude longer than inelastic collision rate limited lifetimes found in the large mass-imbalance system of Yb( 3 P 2 )-Li [12] and an encouraging starting point for further research of Er-Li mixtures in the strongly interacting regime.…”

“…From the Er source heated to about 1050 • C a hot atomic beam is formed. A transversal cooling stage operating on the broad 4f 12 6s 2 ( 3 H 6 ) to 4f 12 ( 3 H 6 )6s6p ( 1 P 1 ) transition at 401 nm limits the initial transverse spread to the thermal Er beam. A subsequent Zeeman slowing stage operating on the same transition reduces the longitudinal velocity of the Er atoms.…”

“…A subsequent Zeeman slowing stage operating on the same transition reduces the longitudinal velocity of the Er atoms. A magneto-optical trap (MOT) operating on the narrow 4f 12 6s 2 ( 3 H 6 ) to 4f 12 ( 3 H 6 )6s6p ( 3 P 1 ) intercombination line at 583 nm forms the initial trapping stage. From there the atoms are transferred into a far-off-resonant optical trap (FORT) of crossed, focused beams at 1064 nm and 1070 nm.…”

“…We here present our first results of the experimental realization of a large mass-imbalance mixture of heavy Erbium (Er) and light Lithium (Li) atoms and the discovery of interspecies Feshbach resonances. In previous experiments much effort was spent on similar investigations in ultracold mixtures of heavy Ytterbium (Yb) and light Li [11][12][13]. While these works scanned a large range of isotope combinations, electronic configurations and magnetic field strengths, only a few traces of Feshbach resonances could be detected with limited applicability towards an efficient control of interspecies interactions.…”

Photoassociation of Ultracold CsYb Molecules and Determination of Interspecies Scattering Lengths

“…The metastable Yb atoms may be prepared either by direct excitation on a narrow transition [150] or by excitation to the 3 D 2 state and the subsequent decay to 3 P 2 state [151]. Both groups have observed indications of field-dependent inelastic losses [152,153] but to date no distinct resonances have been found. This is likely due to the suppression of the resonance poles in the presence of inelastic scattering [154,155], which is prevalent in the Li+Yb system.…”