K. Miyake et al., REPULSION BETWEEN CONDUCTION ELECTRONS AS A RELEVANT PERTURBATION AGAINST THE STABILITY OF NON-FERMI-LIQUID FIXED-POINT OF MULTICHANNEL KONDO PROBLEM, Journal of the Physical Society of Japan, 62(8), 1993, pp. 2553-2556
It is shown that a non-Fermi-liquid fixed point of the multichannel Ko
ndo problem is unstable for repulsive interaction at the impurity site
between conduction electrons with different flavors and the same pseu
dospin. The anomalous fixed point is shown, by the perturbative renorm
alization group argument, to move into the strong coupling region with
increasing repulsion. The low-temperature properties at the so-called
''Toulouse limit'' are calculated by the bosonization method to show
that the Fermi-liquid like behavior is recovered quickly as soon as re
pulsion is switched on. This result poses a question as to the reality
of the non-Fermi-liquid state for the multichannel Kondo model which
has been examined extensively so far.