SPIN-FLAVOR SEPARATION AND NON-FERMI-LIQUID BEHAVIOR IN THE MULTICHANNEL KONDO PROBLEM - A LARGE-N APPROACH

We present an analytical solution of a SU(N) x SU(M) generalization of the multichannel single-impurity Kondo model in the limit N --> infin ity, M --> infinity, with gamma = M/N fixed. Non-Fermi-liquid behavior of the single electron Green function and of the local spin and flavo r susceptibilities occurs in both regimes, N less-than-or-equal-to M a nd N > M, with leading critical exponents identical to those found in the conformal field theory solution for all N and M (with M greater-th an-or-equal-to 2). We explain this remarkable agreement and connect it to ''spin-flavor separation,'' the essential feature of the non-Fermi -liquid fixed point.