Selective Mott transition and heavy fermions

TL;DR

This paper investigates the quantum critical behavior of f-electron localization in an extended Anderson lattice, revealing a new energy scale and distinct fluctuation regimes with observable transport signatures.

Contribution

It introduces a detailed analysis of the Mott transition in heavy fermion systems, highlighting a new universality class and energy scale at the quantum critical point.

Findings

Identification of a new energy scale separating universality classes

Massless gauge modes dominate low-energy fluctuations

Quasi-linear resistivity observed in 3D at the QCP

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 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 quasi-linear resistivity in 3D and anomalous exponents lower than T in 2 D. This rather unique feature of the quantum critical regime enables us to make experimentally testable predictions.