Dehybridization transition in Kondo insulators and heavy fermions

TL;DR

This paper reviews the dehybridization transition in Kondo insulators and heavy fermions, explaining how electron interactions lead to effective decoupling of bands and affect their electronic properties, using non-Hermitian theory and LDA+DMFT data.

Contribution

It introduces a new perspective on dehybridization using non-Hermitian systems and analyzes its effects with LDA+DMFT calculations.

Findings

Dehybridization causes spectral and transport property changes.

Non-Hermitian theory provides new insights into the transition.

LDA+DMFT parametrization helps understand correlated electron behavior.

Abstract

In strongly correlated multi-band systems, like inter-metallics, heavy fermions or Kondo insulators, electron-electron and electron-phonon scattering of the electrons in the bands give rise, at finite temperatures, to a damping of these quasi-particles. This is responsible for producing an effective dehybridization between the electrons in the large conduction bands and those in the narrow, correlated band. This dehybridization effect has been used to explain the transport properties of inter-metallics and ARPES experiments in heavy fermions at sufficiently high temperatures. A new insight into this problem has been recently proposed using the theory of non-Hermitian systems. In this note, we review previous work on dehybridization in Kondo insulators and strongly correlated metals within this new perspective. For this purpose, we use a parametrization of the self-energy of the strongly correlated electrons obtained from LDA+DMFT calculations. We discuss the nature of the dehybridization transition and its consequences in the electronic spectrum and transport properties.