Bose-Einstein Condensation of Strontium

Abstract

We report on the attainment of Bose-Einstein condensation with ultracold strontium atoms. We use the (84)Sr isotope, which has a low natural abundance but offers excellent scattering properties for evaporative cooling. Accumulation in a metastable state using a magnetic-trap, narrowline cooling, and straightforward evaporative cooling in an optical trap lead to pure condensates containing 1.5 x 10(5) atoms. This puts (84)Sr in a prime position for future experiments on quantum-degenerate gases involving atomic two-electron systems.

Many-body physics with alkaline-earth Rydberg lattices

“…Attractive interactions between non-degenerate Rydberg states are also appealing fin the context of recently proposed techniques for engineering effective ground state atom interactions by off-resonant Rydberg dressing of Bose-Einstein condenstates [51,52,53]. Quantum degeneracy was recently achieved for strontium atoms [54,55,56]. In contrast to alkali condensates, here Rydberg dressing using the Sr(5sns) states could be used to realize attractive effective ground state atom interactions, which, for example, may permit the creation of three-dimensional bright solitons [57].…”

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

“…The laser cooling, trapping and manipulation of Rb atoms have been wellestablished at the very beginning of the ultracold matter studies [20]. At present the strontium atom is one of the most popular atomic species in ultracold physics [21,22]: for example, the studies of Bose-Einstein condensation of Sr atoms and Bose-Fermi mixtures (of different Sr isotopes) has recently been reported [23][24][25][26][27]. Moreover, the Innsbruck group has developed the STIRAP scheme to produce weakly bound Sr 2 molecules in ground electronic state.…”

Numerical modeling of collisional dynamics of Sr in an optical dipole trap

“…Here, we describe numerical methods appropriate for modeling collisional dynamics in an arbitrary trap in the low-or high-η regime, which can be used for 88 Sr. Our approach builds on the works of Luiten et al [10] and Comparat et al [19]. As a check of the model, we also compare predictions with measurements of forced evaporation in 84 Sr, which has an s-wave scattering length of a 84 = 122.7(3)a 0 [21] and attains a much higher η, which allows direct evaporation to quantum degeneracy [22,23]. This model has also been used to interpret data on collisions involving Sr atoms in metastable states [24] and evaporative cooling of 87 Sr and 88 Sr for quantum degeneracy studies [25,26].…”