Strong Coupling Approach to the Supersymmetric Kondo Model
arXiv:cond-mat/0001002 · doi:10.1016/S0550-3213(00)00419-3
Abstract
We carry out the strong coupling expansion for the SU(N) Kondo model where the impurity spin is represented by a L-shaped Young tableau. Using second order perturbation theory around the strong coupling fixed point it is shown that when the antisymmetric component of the Young-tableau contains more than N/2 entries, the strong-coupling fixed point becomes unstable to a two-stage Kondo effect. By comparing the strong coupling results obtained here with the result using a supersymmetric large N expansion, we are also able to confirm the validity of the the supersymmetric formalism for mixed symmetry Kondo models.
References and corrections added. Two column version http://www.physics.rutgers.edu/~coleman/strx.ps.gz