Comment on "A Recursive Parametrisation of Unitary Matrices"
  In 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. 
Kazuyuki Fujii (Yokohama City University)