Luttinger liquid of trimers in Fermi gases with unequal masses.
We investigate one dimensional attractive Fermi gases in spin-dependent optical lattices. We show that three-body bound states--"trimers"--exist as soon as the two tunneling rates are different. We calculate the binding energy and the effective mass of a single trimer. We then show numerically that for finite and commensurate densities n(up) = n(down)/2 an energy gap appears, implying that the gas is a one-component Luttinger liquid of trimers with suppressed superfluid correlations. The boundaries of this novel phase are given. We discuss experimental situations to test our predictions.
Orso
Giuliano
G
Laboratoire de Physique Théorique et Modèles statistiques, Université Paris-Sud, 91405 Orsay, France.
Burovski
Evgeni
E
Jolicoeur
Thierry
T