Interaction-induced decoherence in non-Hermitian quantum walks of ultracold bosons
Kevin Rapedius, H. J. Korsch · Physical Review A · 2012
We study the decoherence caused by particle interaction for a conceptually simple model, a quantum walk on a bipartite one-dimensional lattice with decay from every second site. The corresponding noninteracting (linear) system has been shown to have a topological transition described by the average displacement before decay. Here, we use this topological quantity to distinguish coherent quantum dynamics from incoherent classical dynamics caused by a breaking of the translational symmetry. Furthermore, we analyze the behavior by means of a rate equation providing a quantitative description of the incoherent nonlinear dynamics.