COEXISTENCE OF FERMI-LIQUID AND MAGNETISM IN THE UNDERSCREENED KONDO PROBLEM

The underscreened Kondo impurity problem provides an idealized model where Fermi-liquid excitations coexist with magnetic degrees of freedom, completely decoupling from them at low frequency. We show that a simple two-fluid approach works properly in this simple case and discuss the extent to which this kind of decoupling can be used to understand the coexistence of quasiparticle excitations and low-energy magnetic fluctuations in heavy-fermion compounds.