Kondo-Ising and Tight-Binding Models for TmB4

In \(TmB_4\), localized electrons with a large magnetic moment interact with metallic electrons in boron-derived bands. We examine the nature of \(TmB_4\) using full-relativistic ab-initio density functional theory calculations, approximate tight-binding Hamiltonian results, and the development of a...

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Bibliographic Details
Published inarXiv.org
Main Authors Shin, John, Schlesinger, Zack, B Sriram Shastry
Format Paper Journal Article
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 29.04.2017
Subjects
Binding
Boron
Conduction electrons
Density functional theory
Electron spin
Fermi surfaces
Ising model
Magnetic moments
Physics - Strongly Correlated Electrons
Relativistic theory
System effectiveness
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Summary:In \(TmB_4\), localized electrons with a large magnetic moment interact with metallic electrons in boron-derived bands. We examine the nature of \(TmB_4\) using full-relativistic ab-initio density functional theory calculations, approximate tight-binding Hamiltonian results, and the development of an effective Kondo-Ising model for this system. Features of the Fermi surface relating to the anisotropic conduction of charge are discussed. The observed magnetic moment \(\sim 6 \, \mu_B\) is argued to require a subtle crystal field effect in metallic systems, involving a flipped sign of the effective charges surrounding a Tm ion. The role of on-site quantum dynamics in the resulting Kondo-Ising type "impurity" model are highlighted. From this model, elimination of the conduction electrons will lead to spin-spin (RKKY-type) interaction of Ising character required to understand the observed fractional magnetization plateaus in \(TmB_4\).
ISSN:2331-8422
DOI:10.48550/arxiv.1702.07381