Itinerant vs Localized Heavy-Electron Magnetism

TL;DR

This paper investigates the transition between itinerant and localized heavy-electron states within the magnetically ordered phase of the Kondo-Heisenberg lattice, revealing flat bands and magnetic fluctuations through advanced computational methods.

Contribution

It introduces a combined computational approach to map the phase diagram and electronic structure of heavy-electron systems, highlighting the itinerant-localized transition within magnetic phases.

Findings

Flat bands appear near the transition point.

Strong local magnetic fluctuations emerge at the transition.

The phase diagram explains experimental observations in several heavy-electron compounds.

Abstract

It is demonstrated that itinerant-localized transition of heavy electrons occurs inside the magnetically ordered phase of the Kondo-Heisenberg lattice. The phase diagram and electronic structure are derived by means of the continuous-time quantum Monte Carlo combined with the dynamical mean-field theory. Around the itinerant-localized transition, nearly flat bands appear on the Fermi surface with almost vanishing quasi-particle renormalization factor. At the same time, there emerges a strong local magnetic fluctuation with a minute energy scale. Considering both antiferromagnetic and ferromagnetic Heisenberg interactions, coherent understanding is achieved on rich phase diagrams observed in CeRh$_{1-x}$Co$_x$In$_5$, CeRu$_2$(Si$_x$Ge$_{1-x}$)$_2$, UGe$_2$ and CeT$_2$Al$_{10}$ (T=Fe,Ru,Os).