title: Optical conductivity of the half-filled hubbard chain
abstract: We combine well-controlled analytical and numerical methods to determine the optical conductivity of the one-dimensional Mott-Hubbard insulator at zero temperature. A dynamical density-matrix renormalization group method provides the entire absorption spectrum for all but very small coupling strengths. In this limit we calculate the conductivity analytically using exact field-theoretical methods. Above the Lieb-Wu gap the conductivity exhibits a characteristic square-root increase. For small to moderate interactions, a sharp maximum occurs just above the gap. For larger interactions, another weak feature becomes visible around the middle of the absorption band.
authors.affiliation: Fachbereich Physik, Philipps-Universitat Marburg, D-35032 Marburg, Germany.
authors.initials: E
authors.lastname: Jeckelmann
authors.initials: F
authors.lastname: Gebhard
authors.initials: FH
authors.lastname: Essler