Localization of correlated fermions in optical lattices with speckle disorder

TL;DR

This study investigates how speckle disorder affects strongly correlated fermions in optical lattices, revealing disorder-induced localization and the suppression of metal-insulator transitions, with implications for experimental realizations.

Contribution

We extend statistical dynamical mean-field theory to include speckle disorder, providing a comprehensive phase diagram and insights into localization and correlation effects.

Findings

Disorder suppresses the correlation-driven metal-insulator transition.

Speckle disorder causes localization detectable via local density of states.

The Anderson-Mott and Mott insulators are not smoothly connected under speckle disorder.

Abstract

Strongly correlated fermions in three- and two-dimensional optical lattices with experimentally realistic speckle disorder are investigated. We extend and apply the statistical dynamical mean-field theory, which treats local correlations non-perturbatively, to incorporate on-site and hopping-type randomness on equal footing. Localization due to disorder is detected via the probability distribution function of the local density of states. We obtain a complete paramagnetic ground state phase diagram for experimentally realistic parameters and find a strong suppression of the correlation-induced metal insulator transition due to disorder. Our results indicate that the Anderson-Mott and the Mott insulator are not continuously connected due to the specific character of speckle disorder. Furthermore, we discuss the effect of finite temperature on the single-particle spectral function.