1201.1958 (Weiran Li et al.)

Bose Gases Near Unitarity    [PDF]

Weiran Li, Tin-Lun Ho

We study the properties of strongly interacting Bose gases at the density and
temperature regime when the three-body recombination rate is substantially
reduced. In this regime, one can have a Bose gas with all particles in
scattering states (i.e. the "upper branch") with little loss even at unitarity
over the duration of the experiment. We show that because of bosonic
enhancement, pair formation is shifted to the atomic side of the original
resonance (where scattering length $a_s<0$), opposite to the fermionic case. In
a trap, a repulsive Bose gas remains mechanically stable when brought across
resonance to the atomic side until it reaches a critical scattering length
$a_{s}^{\ast}<0$. For $a_supper branch bosons surrounded by an outer layer of equilibrium phase. The
conditions of low three-body recombination requires that the particle number
$N<\alpha (T/\omega)^{5/2}$ in a harmonic trap with frequency $\omega$, where
$\alpha$ is a constant.

View original: http://arxiv.org/abs/1201.1958