219 research outputs found
Suppression of molecular decay in ultracold gases without Fermi statistics
We study inelastic processes for ultracold three-body systems in which only
one interaction is resonant. We have found that the decay rates for weakly
bound molecules due to collisions with other atoms can be suppressed not only
without fermionic statistics but also when bosonic statistics applies. In
addition, we show that at ultracold temperatures three-body recombination
involving a single resonant pair of atoms leads mainly to formation of weakly
bound molecules which, in turn, are stable against decay. These results
indicate that recombination in three-component atomic gases can be used as an
efficient mechanism for molecular formation, allowing the achievement of high
molecular densities
Mass Dependence of Ultracold Three-Body Collision Rates
We show that many aspects of ultracold three-body collisions can be
controlled by choosing the mass ratio between the collision partners. In the
ultracold regime, the scattering length dependence of the three-body rates can
be substantially modified from the equal mass results. We demonstrate that the
only non-trivial mass dependence is due solely to Efimov physics. We have
determined the mass dependence of the three-body collision rates for all
heteronuclear systems relevant for two-component atomic gases with resonant
s-wave interspecies interactions, which includes only three-body systems with
two identical bosons or two identical fermions
Efimov Trimer Formation via Ultracold Four-body Recombination
We discuss the collisional formation of Efimov trimers via ultracold
four-body recombination. In particular, we consider the reaction A+A+A+B->A3+B
with A and B ultracold atoms. We obtain expressions for the four-body
recombination rate and show that it reflects the three-body Efimov physics
either as a function of collision energy or as a function of the two-body
s-wave scattering length between A atoms. In addition, we briefly discuss
issues important for experimentally observing this interesting and relatively
unexplored process.Comment: 5 pages, 3 figure
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