Finite-frequency optical absorption in 1D conductors and mott-hubbard insulators
The frequency-dependent conductivity is studied for the one-dimensional Hubbard model, using a selection rule, the Bethe ansatz, and symmetries associated with conservation laws. For densities where the system is metallic the absorption spectrum has two contributions, a Drude peak at omega = 0 separated by a pseudogap from a broad absorption band whose lower edge is characterized by a nonclassical critical exponent. Our findings shed new light on the "far infrared puzzle" and other optical properties of metallic organic chain compounds.
Carmelo
JM
CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 and Department of Physics, University of Evora, Apartado 94, P-7002-554 Evora, Portugal.
Peres
NM
Sacramento
PD