Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}

SmB_{6}, a well-known Kondo insulator, has been proposed to be an ideal topological insulator with states of topological character located in a clean, bulk electronic gap, namely, the Kondo-hybridization gap. Since the Kondo gap arises from many-body electronic correlations, SmB_{6} would be placed...

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Main Authors: E. Frantzeskakis, N. de Jong, B. Zwartsenberg, Y. K. Huang, Y. Pan, X. Zhang, J. X. Zhang, F. X. Zhang, L. H. Bao, O. Tegus, A. Varykhalov, A. de Visser, M. S. Golden
Format: Article
Language:English
Published: American Physical Society 2013-12-01
Series:Physical Review X
Online Access:http://doi.org/10.1103/PhysRevX.3.041024
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author E. Frantzeskakis
N. de Jong
B. Zwartsenberg
Y. K. Huang
Y. Pan
X. Zhang
J. X. Zhang
F. X. Zhang
L. H. Bao
O. Tegus
A. Varykhalov
A. de Visser
M. S. Golden
author_facet E. Frantzeskakis
N. de Jong
B. Zwartsenberg
Y. K. Huang
Y. Pan
X. Zhang
J. X. Zhang
F. X. Zhang
L. H. Bao
O. Tegus
A. Varykhalov
A. de Visser
M. S. Golden
author_sort E. Frantzeskakis
collection DOAJ
description SmB_{6}, a well-known Kondo insulator, has been proposed to be an ideal topological insulator with states of topological character located in a clean, bulk electronic gap, namely, the Kondo-hybridization gap. Since the Kondo gap arises from many-body electronic correlations, SmB_{6} would be placed at the head of a new material class: topological Kondo insulators. Here, for the first time, we show that the k-space characteristics of the Kondo-hybridization process is the key to unraveling the origin of the two types of metallic states experimentally observed by angle-resolved photoelectron spectroscopy (ARPES) in the electronic band structure of SmB_{6}(001). One group of these states is essentially of bulk origin and cuts the Fermi level due to the position of the chemical potential 20 meV above the lowest-lying 5d-4f hybridization zone. The other metallic state is more enigmatic, being weak in intensity, but represents a good candidate for a topological surface state. However, before this claim can be substantiated by an unequivocal measurement of its massless dispersion relation, our data raise the bar in terms of the ARPES resolution required, as we show there to be a strong renormalization of the hybridization gaps by a factor 2–3 compared to theory, following from the knowledge of the true position of the chemical potential and a careful comparison with the predictions from recent local-density-approximation (LDA)+Gutzwiller calculations. All in all, these key pieces of evidence act as triangulation markers, providing a detailed description of the electronic landscape in SmB_{6} and pointing the way for future, ultrahigh-resolution ARPES experiments to achieve a direct measurement of the Dirac cones in the first topological Kondo insulator.
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spelling doaj.art-8c805b6537a04a3d977513ad440e3ea82022-12-21T19:22:30ZengAmerican Physical SocietyPhysical Review X2160-33082013-12-013404102410.1103/PhysRevX.3.041024Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}E. FrantzeskakisN. de JongB. ZwartsenbergY. K. HuangY. PanX. ZhangJ. X. ZhangF. X. ZhangL. H. BaoO. TegusA. VarykhalovA. de VisserM. S. GoldenSmB_{6}, a well-known Kondo insulator, has been proposed to be an ideal topological insulator with states of topological character located in a clean, bulk electronic gap, namely, the Kondo-hybridization gap. Since the Kondo gap arises from many-body electronic correlations, SmB_{6} would be placed at the head of a new material class: topological Kondo insulators. Here, for the first time, we show that the k-space characteristics of the Kondo-hybridization process is the key to unraveling the origin of the two types of metallic states experimentally observed by angle-resolved photoelectron spectroscopy (ARPES) in the electronic band structure of SmB_{6}(001). One group of these states is essentially of bulk origin and cuts the Fermi level due to the position of the chemical potential 20 meV above the lowest-lying 5d-4f hybridization zone. The other metallic state is more enigmatic, being weak in intensity, but represents a good candidate for a topological surface state. However, before this claim can be substantiated by an unequivocal measurement of its massless dispersion relation, our data raise the bar in terms of the ARPES resolution required, as we show there to be a strong renormalization of the hybridization gaps by a factor 2–3 compared to theory, following from the knowledge of the true position of the chemical potential and a careful comparison with the predictions from recent local-density-approximation (LDA)+Gutzwiller calculations. All in all, these key pieces of evidence act as triangulation markers, providing a detailed description of the electronic landscape in SmB_{6} and pointing the way for future, ultrahigh-resolution ARPES experiments to achieve a direct measurement of the Dirac cones in the first topological Kondo insulator.http://doi.org/10.1103/PhysRevX.3.041024
spellingShingle E. Frantzeskakis
N. de Jong
B. Zwartsenberg
Y. K. Huang
Y. Pan
X. Zhang
J. X. Zhang
F. X. Zhang
L. H. Bao
O. Tegus
A. Varykhalov
A. de Visser
M. S. Golden
Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
Physical Review X
title Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
title_full Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
title_fullStr Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
title_full_unstemmed Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
title_short Kondo Hybridization and the Origin of Metallic States at the (001) Surface of SmB_{6}
title_sort kondo hybridization and the origin of metallic states at the 001 surface of smb 6
url http://doi.org/10.1103/PhysRevX.3.041024
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