title: Non-Gaussian spatial correlations dramatically weaken localization.
abstract: We perform variational studies of the interaction-localization problem to describe the interaction-induced renormalizations of the effective (screened) random potential seen by quasiparticles. Here we present results of careful finite-size scaling studies for the conductance of disordered Hubbard chains at half-filling and zero temperature. While our results indicate that quasiparticle wave functions remain exponentially localized even in the presence of moderate to strong repulsive interactions, we show that interactions produce a strong decrease of the characteristic conductance scale g^{*} signaling the crossover to strong localization. This effect, which cannot be captured by a simple renormalization of the disorder strength, instead reflects a peculiar non-Gaussian form of the spatial correlations of the screened disordered potential, a hitherto neglected mechanism to dramatically reduce the impact of Anderson localization (interference) effects.
authors.affiliation: Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: H
authors.initials: H
authors.lastname: Javan Mard
authors.affiliation: Institut für Theoretische Physik, Technische Universität Dresden, 01062 Dresden, Germany.
authors.forename: E C
authors.initials: EC
authors.lastname: Andrade
authors.affiliation: Instituto de Física Gleb Wataghin, Unicamp, R. Sérgio Buarque de Holanda, 777, Campinas, SP 13083-859, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Miranda
authors.affiliation: Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: V
authors.initials: V
authors.lastname: Dobrosavljević