2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/58070In this note we make a comment on the paper by Jarlskog (math-ph/0504049) in which she gave a parametrisation to unitary matrices. Namely, we show that her recursive method is essentially obtained by the canonical coordinate of the second kind in the Lie group theory, and propose a problem on constructing unitary gates in quantum computation by making use of the parametrisation.Latex files, 6 pages. Typos correctedMathematical PhysicsQuantum Physicstext