Pd. Sacramento et Vr. Vieira, LATTICE COHERENCE VERSUS INCOHERENT METAL IN THE LATTICE N-CHANNEL KONDO MODEL, Physical review. B, Condensed matter, 58(17), 1998, pp. 11119-11122
We consider the lattice extension of the SU(N) x SU(M) generalization
of the multichannel Kondo problem. Within the noncrossing approximatio
n, the effect of the lattice is of order 1/N and, therefore, the behav
ior of the system is qualitatively the same as for the single-impurity
case. The density of states at the Fermi energy is finite, leading to
an incoherent metal. At sufficiently low temperatures lattice coheren
ce should prevail. We estimate the temperature at which the spin and c
hannel susceptibilities have an instability, summing analytically the
ladder series for the spin and channel vertices. We find an antiferrom
agnetic instability and no ferromagnetic instability in the spin susce
ptibility and a zero-momentum instability in the channel susceptibilit
y. [S0163-1829(98)08641-X].