2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/93454We argue that several claims of paper Phys. Rev. Lett 79, 1953 (1997), by Lu-Ming Duan and Guang-Can Guo, are questionable. In particular we stress that the environmental noise considered by the authors belongs to a very special class2 pages, RevTeXQuantum Physicstext