Total spin and antiferromagnetic correlation in the Kondo model

In this paper, we present two theorems on the total spin and the sign of the transverse spin-spin correlation. For a half-filled single-channel or multichannel Kondo model with or without a Hubbard term for conduction electrons, we calculate the total spin in the ground state, which depends on the lattice, on the distribution of the localized electron, and on the sign of the exchange coupling J. The stability of these magnetic properties against Coulomb interaction between conduction electrons is also discussed.