Dependence of the charge transport in tilted chains on the choice of two-body interaction

TL;DR

This paper investigates how different two-body interactions affect charge transport in tilted chains of spinless fermions, revealing that pair-hopping interactions can significantly accelerate charge dynamics compared to density-density interactions.

Contribution

It decomposes the two-body interaction into commuting and noncommuting parts, deriving an explicit form for the noncommuting part and analyzing its impact on charge transport.

Findings

Pair-hopping interactions can speed up charge dynamics by several orders of magnitude.

The noncommuting part of the interaction decreases with tilt and influences correlated hopping.

Replacing density-density interaction with pair-hopping alters the charge transport behavior.

Abstract

We study tilted chains of spinless fermions in the presence of the nearest-neighbor density-density interaction for which the noninteracting counterpart displays Stark localization. We demonstrate that the latter two-body interaction can be decomposed into two (orthogonal) parts which, respectively, commute and do not commute with the single-particle Hamiltonian. We derive an explicit form of the noncommuting part that decreases with tilt and describes the nearest-neighbor correlated hopping and the pair-hopping interaction. When the density-density coupling is replaced by the pair-hopping interaction of the same magnitude then the charge dynamics may be faster by a few orders of magnitude than in the original model.