ONE-, TWO-, AND THREE-CHANNEL KONDO EFFECTS FOR A MODEL CE3+ IMPURITY IN A METAL

摘要

We present studies of a simple Anderson model Hamiltonian for Ce3+ ions in cubic symmetry with three configurations (f(0),f(1),f(2)). In different parameter regimes, our model Hamiltonian maps;to the one-, two-, and three-channel spin-1/2 Kondo models. Using third-order scaling (perturbative renormalization group) analysis, we study the stability of the non-Fermi-liquid fixed point of the two-channel Kondo model for Ce3+ ions in cubic symmetry against the one-channel Kondo interaction. Using the noncrossing approximation (NCA), we also report detailed studies for our simplified model of the competition between the Fermi-liquid fixed point of the one-channel Kondo model and the non-Fermi fixed points of the two- and three-channel Kondo models. We provide the phase diagram in the model parameter space and study the thermodynamics and the transport properties of our simplified model Hamiltonian. Thermodynamics and transport coefficients show distinct behaviors for different numbers of channels. We confirm in detail that the NCA is a valid numerical method for the overcompensated multichannel S-l=1/2 Anderson models. Our model study might be relevant to the non-Fermi-liquid alloy Ce1-xLaxCu2.2Si2. [References: 76]