title: Nonequilibrium quantum dynamics of a charge carrier doped into a Mott insulator.
abstract: We study real-time dynamics of a charge carrier introduced into an undoped Mott insulator propagating under a constant electric field F on the t-J ladder and a square lattice. We calculate the quasistationary current. In both systems an adiabatic regime is observed followed by a positive differential resistivity (PDR) at moderate fields where the carrier mobility is determined. Quantitative differences between the ladder and two-dimensional (2D) systems emerge when at large fields both systems enter the negative differential resistivity (NDR) regime. In the ladder system Bloch-like oscillations prevail, while in two dimensions the current remains finite, proportional to 1/F. The crossover between the PDR and NDR in two dimensions is accompanied by a change of the spatial structure of the propagating spin polaron.
authors.affiliation: Institute of Physics, University of Silesia, 40-007 Katowice, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Mierzejewski
authors.forename: L
authors.initials: L
authors.lastname: Vidmar
authors.forename: J
authors.initials: J
authors.lastname: Bonča
authors.forename: P
authors.initials: P
authors.lastname: Prelovšek