RESISTIVITY OF A ONE-DIMENSIONAL INTERACTING QUANTUM FLUID

The frequency and temperature dependence of the conductivity of a one-dimensional fermion system with attractive interactions is studied by using a renormalization-group technique. At half filling the real part of the conductivity has it both a delta(omega) part and a divergent frequency behavior omega(-nu) at finite frequencies, where nu is a nonuniversal exponent depending on the interactions. For the particular case of the attractive Hubbard model, logarithmic corrections appear and the conductivity behaves as 1/[omega-ln2(omega)], plus a delta(omega) part. Away from half filling the conductivity has a delta(omega) part and a gap up to a critical frequency-omega(c), where omega(c), is proportional to the doping with a prefactor depending on the interactions. The results obtained for the fermion model can be straightforwardly extended to the conductivity of an interacting one-dimensional boson model.