Analytical results for the Coqblin-Schrieffer model with generalized magnetic fields

Using the approach alternative to the traditional thermodynamic Bethe ansatz, we derive analytical expressions for the free energy of Coqblin-Schrieffer model with arbitrary magnetic and crystal fields. In the Appendix we calculate the zero-temperature magnetic susceptibility for two concrete crystal-field patterns. One of the patterns describes the field generated crossover from the SU(4) to the SU(2) symmetry in the SU(4)-symmetric model.