Laboratoire de Physique Théorique
Toulouse - UMR 5152

Despite a strong theoretical effort in the last decades, the origin of non-Fermi liquid behavior in many heavy fermion compounds remains unclear. The observation that non-Fermi liquid behavior is usually found in the proximity of a T=0 change in the ground state strongly suggests that the origin is an underlying quantum critical point. On the other hand a satisfactory microscopic theory of this QCP has been so far elusive. We present a T=0 (dynamical) mean field theory of these systems that allows to identify the QCP as an orbital selective Mott transition. This picture accounts for a series of experimental observations that we will discuss.