INFRARED DIVERGENCE AND NON-FERMI LIQUID IN MULTICHANNEL DEGENERATE ANDERSON MODEL

As a straightforward extention of the study on infrared divergences in pseudo-particle spectra in the single-channel degenerate impurity And erson model, those of the multichannel model are examined with use of the expansion from the large limit of the spin-orbital degeneracy N. A nalysis with the most divergent terms in the expansion shows that expo nents of spectra of the. slave boson and the pseudo-fermion in the M-c hannel model with 1 less than or equal to M much less than N are given respectively by 1 - n(f)(2)M/N and (2n(f)-n(f)(2))M/N, where n(f) is the average number of localized electrons at the impurity site. When M = 1, the results recover those obtained earlier in the single channel model. In the limits, n(f) --> 1 and M-2 much less than 1, these resu lts tend to those obtained by the non-crossing approximation (NCA) stu dy. It also shows that the scattering rate of the conduction electrons in the M-channel model includes infrared divergent terms proportional to (1 - n(f))(1 - M-2) in contrast to the absence of infrared diverge nt terms in the single-channel model.