Abstract
We study real-time dynamics of a charge carrier introduced into an undoped Mott insulator propagating under a constant electric field on the 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 . The crossover between the PDR and NDR in two dimensions is accompanied by a change of the spatial structure of the propagating spin polaron.
- Received 18 February 2011
DOI:https://doi.org/10.1103/PhysRevLett.106.196401
© 2011 American Physical Society