Diagonalisation of the generalised Anderson model

Abstract
Using the Bethe ansatz technique the authors have diagonalised Coleman's (1984-5) generalisation of the single-impurity infinite-U Anderson model. A special limit of their solution extends earlier results for the SU(N) Coqblin-Schreiffer model to multiple f occupancy. The authors have calculated the thermodynamics of the generalised Anderson model and find that as they take the degeneracy to infinity maintaining a finite filling factor of the f state the cross-over to strong coupling sharpens into a phase transition and the thermodynamics converges to the mean-field solution valid at infinity degeneracy.