Selective Mott transition and heavy fermions

Abstract

Starting with an extended version of the Anderson lattice where the $f$ electrons are allowed a weak dispersion, we examine the possibility of a Mott localization of the $f$ electrons for a finite value of the hybridization $V$. We study the fluctuations at the quantum critical point (QCP) where the $f$ electrons localize. We find that they are in the same universality class as for the Kondo breakdown QCP, with the following notable features. The quantum critical regime sees the appearance of an additional energy scale separating two universality classes. In the low energy regime, the fluctuations are dominated by massless gauge modes, while in the intermediate energy regime, the fluctuations of the modulus of the order parameter are the most relevant ones. In the latter regime, electric transport simplifies drastically, leading to a quasilinear resistivity in three dimensional and anomalous exponents lower than $T$ in two dimensional. This rather unique feature of the quantum critical regime enables us to make experimentally testable predictions.