J. Phys. I France 4 (1994) 921-938
A note on quasielastic neutron scatteringG. Coddens
Laboratoire Léon Brillouin, C.E.A./C.N.R.S., F-91191 Gif-sur-Yvette Cedex, France Neutron Scattering Project, LI.K.W., University of Antwerp, B-2610-Wilrijk, Belgium
(Received 7 October 1993, revised 11 February 1994, accepted 24 February 1994)
We present a theorem that in coherent quasielastic neutron scattering on a confined and limited system of identical particles only the configuration-configuration correlations have to be examined without any hindsight on the distribution of the particles inside the configuration. This constitutes a strong simplification with respect to the problem where all particle-particle correlations would have to be accounted for. The method is illustrated on an example of correlated hopping on a piece of an octagonal quasiperiodic tiling. With some modifications the method can also be used for incoherent scattering. A further simplification of the calculations both for coherent and incoherent scattering functions is obtained by introducing a new matrix notation that allows fully for the symmetry properties of the problem.
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