Ultracold atoms in one-dimensional optical lattices approaching the Tonks-Girardeau regime
Lode Pollet
Subatomic and Radiation Physics Department, Ghent University, Proeftuinstraat 86, 9000 Gent, Belgium
Recent experiments on ultracold atomic alkali gases in a
one-dimensional optical lattice have demonstrated the transition
from a gas of soft-core bosons to a Tonks-Girardeau gas
in the hard-core limit, where one-dimensional bosons
behave just like fermions.
We have studied the underlying many-body physics
through numerical simulations which accommodate both
the soft-core and hard-core limits in one single framework.
We find that the Tonks-Girardeau gas is reached only
at the strongest optical lattice potentials.
Results for slightly higher densities,
where the gas develops a Mott-like phase already
at weaker optical lattice potentials,
show that these Mott-like short range correlations
do not enhance the convergence to the hard-core limit.
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