2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/90628We prove that the stationarity and the ergodicity of a quantum source are preserved by any trace-preserving completely positive linear map of the tensor product form ${\cal E}^{\otimes m}$, where a copy of ${\cal E}$ acts locally on each spin lattice site. We also establish ergodicity criteria for so called classically-correlated quantum sources.9 pages, no figures; typos corrected, appendix and references addedQuantum Physicstext