Charge Kondo effect toward a non-Fermi-liquid fixed point in the orbitally degenerate exchange model

Abstract

We show that a Kondo-type model with an orbital degeneracy has a new non-Fermi-liquid fixed point. Near the fixed point the spin degrees of freedom are completely quenched, and the residual charge degrees of freedom lead to the multi-channel Kondo effect. Anomalous behavior appears in electric and thermal properties, but the magnetic susceptibility should show the local Fermi-liquid behavior. The non-Fermi-liquid fixed point becomes unstable against perturbations breaking the particle-hole symmetry. We derive these results using the third-order scaling for a spherically symmetric model with a fictitious spin. In contrast to the Coqblin-Schrieffer model, the present model respects different time-reversal properties of multipole operators.

4 pages, 2 eps figures, to appear in J. Phys. Soc. Jpn. 68 No.6

References in corpus (6)

• SU(4) Theory for Spin Systems with Orbital Degeneracy
• SU(4) spin-orbit critical state in one dimension
• Thermodynamics of the one-dimensional SU(4) symmetric spin-orbital model
• Fluctuation Effects on the Quadrupolar Ordering in Magnetic Field
• Perturbative renormalization of multi-channel Kondo-type models
• Orbital Kondo Effect in Ce${}_x$La${}_{1-x}$B${}_6$: Scaling Analysis

Cited by in corpus (4)

• Non-Collinear Magnetism due to Orbital Degeneracy and Multipolar Interactions
• Spin-Orbital Wave Excitations in Orbitally Degenerate Exchange Model with Multipolar Interactions
• Hidden non-Fermi liquid behavior due to crystal field quartet
• Crossover between Fermi Liquid and non-Fermi Liquid in Orbitally Degenerate Kondo Systems