NUMERICAL RENORMALIZATION-GROUP STUDY OF PARTICLE-HOLE SYMMETRY-BREAKING IN 2-CHANNEL KONDO PROBLEM - EFFECT OF REPULSION AMONG CONDUCTION ELECTRONS AND POTENTIAL SCATTERING

Particle-hole symmetry breaking perturbation in the two-channel pseudo spin Kondo problem is studied by the numerical renormalization-group m ethod. It is shown that the repulsion among conduction electrons at th e impurity site and the single particle potential are relevant perturb ations against the conventional non-Fermi-liquid fixed point. Although the repulsion (potential) with realistic strength prevents the oversc reening of the pseudospin, it induces in turn a real spin, which is al so overscreened again. Thus the real spin susceptibility becomes anoma lous, contrary to the conventional two-channel Kondo problem.