title: Fate of 1D spin-charge separation away from Fermi points.
abstract: We consider the dynamic response functions of interacting one dimensional spin-1/2 fermions at arbitrary momenta. We build a nonperturbative zero-temperature theory of the threshold singularities using mobile impurity Hamiltonians. The interaction induced low-energy spin-charge separation and power-law threshold singularities survive away from Fermi points. We express the threshold exponents in terms of the spinon spectrum.
authors.affiliation: Department of Physics, Yale University, 217 Prospect Street, New Haven, Connecticut 06520, USA.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Schmidt
authors.forename: Adilet
authors.initials: A
authors.lastname: Imambekov
authors.forename: Leonid I
authors.initials: LI
authors.lastname: Glazman