Kondo breakdown in multi-orbital Anderson lattices induced by destructive hybridization interference

TL;DR

This paper investigates how destructive hybridization interference in multi-orbital Anderson lattices can suppress heavy Fermi liquid formation, leading to a Kondo breakdown and non-Fermi liquid behavior at quantum critical points.

Contribution

It reveals that quantum interference effects can induce a Kondo breakdown in multi-band models, contrasting with single impurity behavior, and demonstrates the emergence of orbital selective Mott phases.

Findings

Suppression of heavy Fermi liquid at high symmetry points.

Emergence of a non-Fermi liquid spectrum with power-law behavior.

Existence of an orbital selective Mott phase with local criticality.

Abstract

In this paper we consider a multi band extension to the periodic Anderson model. We use a single site DMFT(NRG) in order to study the impact of the conduction band mediated effective hopping of the correlated electrons between the correlated orbitals onto the heavy Fermi liquid formation. Whereas the hybridization of a single impurity model with two distinct conduction bands always adds up constructively, $T_{K}\propto \exp(-\mathrm{const}\, U/(\Gamma_1+\Gamma_2))$, we show that this does not have to be the case in lattice models, where, in remarkable contrast, also an low-energy Fermi liquid scale $T_0\propto \exp(-\mathrm{const}\, U/(\Gamma_1-\Gamma_2))$ can emerge due to quantum interference effects in multi band models, where $U$ denotes the local Coulomb matrix element of the correlated orbitals and $\Gamma_i$ the local hybridization strength of band $i$. At high symmetry points, heavy Fermi liquid formation is suppressed which is associated with a breakdown of the Kondo effect. This results in an asymptotically scale-invariant (i.e., power-law) spectrum of the correlated orbitals $\propto|\omega|^{1/3}$, indicating non-Fermi liquid properties of the quantum critical point, and a small Fermi surface including only the light quasi-particles. This orbital selective Mott phase demonstrates the possibility of metallic local criticality within the general framework of ordinary single site DMFT.