Emergence of non-Fermi liquid dynamics through non-local correlations in an interacting disordered system

TL;DR

This paper demonstrates a quantum critical point in an interacting disordered system where Kondo screening is destroyed, leading to non-Fermi liquid behavior due to strong correlations and disorder effects, identified via advanced computational methods.

Contribution

It provides evidence of a Kondo destruction quantum critical point in the Anderson-Hubbard model with disorder, highlighting a new non-Fermi liquid regime and a unique crossover energy scale.

Findings

Identification of a vanishing energy scale at the QCP

Observation of non-Fermi liquid behavior near the QCP

Distribution of Kondo scales indicates Kondo destruction scenario

Abstract

We provide strong evidence of a quantum critical point (QCP) associated with the destruction of Kondo screening in the Anderson-Hubbard model for interacting electrons with quenched disorder. A unique crossover energy scale, $\omega^*$ separating the Fermi liquid and non-Fermi liquid (nFL) scattering dynamics on the metallic side of the quantum critical fan is identified. The scale vanishes at the disorder driven QCP. We interpret our results by measuring the distribution of Kondo scales and find that the QCP occurs when this distribution acquires a finite intercept, indicating a Kondo destruction scenario, albeit distinct from the local QCP picture. The nFL behavior is shown to stem from an interplay of strong electron-electron interactions and the systematic inclusion of short-range dynamical fluctuations induced by the underlying random potential. The results have been obtained through a computational framework based on the typical medium dynamical cluster approximation.