Dj. Siminovitch et S. Habot, AN NMR ROTATION OPERATOR DISENTANGLEMENT STRATEGY FOR ESTABLISHING PROPERTIES OF THE EULER-RODRIGUES PARAMETERS, Journal of physics. A, mathematical and general, 30(7), 1997, pp. 2577-2584
A disentanglement of the rotation operator introduced by Santiago and
Vaidya is used to prove the composition rule for the Euler-Rodrigues p
arameters in a representation-independent manner. It is also shown tha
t one of the Santiago and Vaidya disentangling coefficients embodies t
he Darboux transformation of differential geometry, which is equivalen
t to stereographic projection of the Bloch sphere onto the complex pla
ne.