Parquet dual fermion approach for the Falicov-Kimball model

Abstract

In the Falicov-Kimball model, a model for (annealed) disorder, we expect weak localization corrections to the optical conductivity. However, we get such weak localization effects only when employing a $pp$-ladder approximation in the dual fermion approach. In the full parquet approach, these $pp$ contributions are suppressed by $ph$-reducible diagrams. For the optical conductivity, we find that the $\overline{ph}$ channel yields the main contribution, even in the region where weak localization in the $pp$ ladder was indicated.