Breakdown of the Kondo Effect in Critical Antiferromagnets

TL;DR

This paper investigates how the Kondo effect breaks down near quantum critical points in antiferromagnetic systems, leading to unscreened impurities and power-law correlations, which may explain anomalous heavy-fermion behaviors.

Contribution

It demonstrates that the Kondo effect can break down due to proximity to a quantum critical point, with implications for understanding heavy-fermion compounds.

Findings

Impurity remains unscreened at the quantum critical point.

Power-law decay of impurity correlation functions.

Breakdown of Kondo effect linked to quantum criticality.

Abstract

The breakdown of the Kondo effect may be the origin of the anomalous properties of the heavy-fermion compounds at low temperatures. We study the dynamics of one impurity embedded in an antiferromagnetic host at the quantum critical point and show that the impurity is not screened and develops a power law correlation function. This suggests that the breakdown of the Kondo effect can simply be a consequence of the system's proximity to the quantum critical point.