“…For weak coupling between the two chains one thus expects a slow "prethermalizationlike" dynamics, where the prethermal state actually ap-proaches a nonequilibrium steady state. Finally, we numerically show that the relaxation dynamics is proportional to the square of the coupling between the chains, and inversely proportional to their length, which can be derived within the prethermalization paradigm [30,31]. We thus expect, in the thermodynamic limit, that the current will exist indefinitely.…”