Solution of two channel spin-flavor Kondo model

Abstract

We investigate a model where an impurity couples to both the spin and the flavor currents of the two channel conduction electrons. This model can be used as a prototype model of a magnetic impurity tunneling between two sites in a metal and of some heavy fermion systems where the ground state of the impurity has a fourfold degeneracy. The system is shown to flow to a doubly degenerate non fermi-liquid(NFL) fixed point; the thermodynamic quantities show NFL behaviors, but the transport quantities show fermi liquid (FL) behaviors . A spin-flavor coupling double tensor term is shown to drive the system to one of the two singlet FL fixed points. The relation with SU(4) Coqblin-Schrieffer model is studied. The implications on the possible experiments are given.Comment: 11 pages, REVTEX, no figures. To appear in Phys. Rev. B (Rapid Comm.) July 1, 199