Coulomb repulsion versus Hubbard repulsion in a disordered chain
arXiv:cond-mat/0003338 · doi:10.1007/PL00011105
Abstract
We study the difference between on site Hubbard and long range Coulomb repulsions for two interacting particles in a disordered chain. While Hubbard repulsion can only yield weak critical chaos with intermediate spectral statistics, Coulomb repulsion can drive the two particle system to quantum chaos with Wigner-Dyson spectral statistics. For intermediate strengths U of the two repulsions in one dimension, there is a crossover regime where delocalization and spectral rigidity are maximum, whereas the limits of weak and strong U are characterized by a stronger localization and uncorrelated energy levels.
8 pages, 10 figures