Theory of One-Channel versus Multichannel Kondo Effects forCe3+Impurities

Abstract

We introduce a model for ${\mathrm{Ce}}^{3+}$ impurities in cubic metals which exhibits competition between the Fermi-liquid fixed point of the single-channel Kondo model and the non-Fermi-liquid fixed point of the two- and three-channel Kondo models. Using the noncrossing approximation and scaling theory, we find the following: (i) A possible three-channel Kondo effect between the one- and two-channel regimes in parameter space. (ii) The sign of the thermopower is a fixed point diagnostic. (iii) Our results will likely survive the introduction of additional $f^2$ and conduction states. We apply this model to interpret the non-Fermi-liquid alloy ${\mathrm{La}}_{1-x}{\mathrm{Ce}}_x{\mathrm{Cu}}_{2.2}{\mathrm{Si}}_2$.