Dielectric response of interacting 1D spinless fermions with disorder

Dielectric responses of a one-dimentional electron system are investigated numerically. We treat an interacting one-dimentional spinless fermion model with disorder by using the density matrix renormalization group (DMRG) method which is extended for nonuniform systems. We apply an electric field E to the system and calculate dielectric responses. The dielectric responses of the Mott insulator and the Anderson insulator are calculated. Steplike behaviors in the P-E curve are obtained which correspond to the breakdown of the insulating behavior. For the Mott insulator, the steps originate from the generation of kink pairs. For the Anderson insulator on the other hand, the origin of the steps is the crossing of localized one-particle energy levels. We also treat random systems with interaction. By one-parameter scaling analysis of the susceptibility chi, the metal-insulator transition in an attractively interacting region is confirmed and a phase diagram of the random spinless fermion model is obtained.