Residue Entropy of Overscreen Multi-Channel Kondo Model: a Study of Large K Expansion

We study the residue entropy of overscreen multi-channel Kondo model by means of perturbathe renormalization group. In this field theory framework one must use pseudofermion representation for local spin operator, and the constraint of pseudofermion must be treated properly. We treat the constraint by a method developed recently. In this method the partition function of the Kondo model is separated into proper weighted partition functions of subsystems. We study the overscreen multi-channel Kondo model through M-subsystem. From calculating the residue entropy of M-subsystem, we obtain the residue entropy of original system which agrees with the result of conformal field theory.