Ultracold Collision Properties of Metastable Alkaline-Earth Atoms
A Derevianko, S. G. Porsev, Svetlana A. Kotochigova, Eite Tiesinga, Paul S. Julienne
Ultra-cold collisions of spin-polarized Mg, Ca, and Sr in the metastable 3P2 excited state are investigated. We show the existence of purely long-range potentials, determine the scattering length, and estimate the collisional loss rate as a function of magnetic field. The estimates are based on molecular potentials between 3P2 alkaline-earth atoms obtained from ab initio atomic and molecular structure calculations. The scattering length has a resonance behavior near 100 mT and is positive for magnetic fields below 50 mT. The resonance is due to the appearance of a bound state in the purely long-range interaction potential between two spin-polarized atoms. A model of the loss rate indicates that losses should be smallest near zero magnetic field and for fields slightly larger than the resonance field. Implications for experiments towards quantum degeneracies are given.
, Porsev, S.
, Kotochigova, S.
, Tiesinga, E.
and Julienne, P.
Ultracold Collision Properties of Metastable Alkaline-Earth Atoms, Physical Review Letters
(Accessed December 7, 2023)