Fermi 1D quantum gas: Luttinger liquid approach and spin-charge   separation
  We discuss the properties of quasi-1D quantum gases of fermionic atoms using the Luttinger liquid theory, including the presence of an optical lattice and of a longitudinal trapping potential. We analyze in particular the nature and manifestations of spin-charge separation, where in the case of atoms ``spin'' and ``charge'' refers to two internal atomic states and the atomic mass density, respectively. 
A. Recati, P.O. Fedichev, W. Zwerger, P. Zoller