Solution of two channel spin-flavor Kondo model

TL;DR

This paper analyzes a two-channel spin-flavor Kondo model, revealing its flow to a non-Fermi-liquid fixed point with unique thermodynamic and transport properties, and explores its relation to the SU(4) Coqblin-Schrieffer model.

Contribution

It introduces and solves a two-channel spin-flavor Kondo model, highlighting its non-Fermi-liquid behavior and connection to SU(4) symmetry.

Findings

System flows to a non-Fermi-liquid fixed point.

Thermodynamic quantities exhibit NFL behavior.

Transport quantities show Fermi-liquid behavior.

Abstract

We investigate a model where an impurity couples to both the spin and the flavor currents of the two channel conduction electrons. This model can be used as a prototype model of a magnetic impurity tunneling between two sites in a metal and of some heavy fermion systems where the ground state of the impurity has a fourfold degeneracy. The system is shown to flow to a doubly degenerate non fermi-liquid(NFL) fixed point; the thermodynamic quantities show NFL behaviors, but the transport quantities show fermi liquid (FL) behaviors . A spin-flavor coupling double tensor term is shown to drive the system to one of the two singlet FL fixed points. The relation with SU(4) Coqblin-Schrieffer model is studied. The implications on the possible experiments are given.