Magnetic impurity in an itinerant Anti-Ferromagnet: Undressing the Kondo effect

We study the undressing of the Kondo effect in the aniferromagnetic phase of an itinerant metal. Expressed in terms of the quasiparticles of the AF, the Kondo interaction induces a new relevant operator that leads to incomplete screening and the ground state is no longer a spin singlet. We show how this comes about by expressing the exchange Hamiltonian in terms of the irreducible representation of the square lattice antiferromagnet and performing a renormalisation group calculation to obtain the ground state properties.