Surface Local Impurity Scattering as a Probe for Topological Kondo Insulators

Fuente: arXiv
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Autori principali: Wang, C. -C. Joseph, Julien, Jean-Pierre, Balatsky, A. V., Zhu, Jian-Xin
Natura: Preprint
Pubblicazione: 2014
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author Wang, C. -C. Joseph
Julien, Jean-Pierre
Balatsky, A. V.
Zhu, Jian-Xin
author_facet Wang, C. -C. Joseph
Julien, Jean-Pierre
Balatsky, A. V.
Zhu, Jian-Xin
contents Shortly after the discovery of topological band insulators, topological Kondo insulators (TKIs) have also been theoretically predicted. The latter has ignited revival interest in the properties of Kondo insulators. Currently, the feasibility of topological nature in SmB$_6$ has been intensively analyzed by several complementary probes. Here by starting with a minimal-orbital Anderson lattice model, we explore the local electronic structure in a Kondo insulator. We show that the two strong topological regimes sandwiching the weak topological regime give rise to a single Dirac cone, which is located near the center or corner of the surface Brillouin zone. We further find that, when a single impurity is placed on the surface, low-energy resonance states are induced in the weak scattering limit for the strong TKI regimes and the resonance level moves monotonically across the hybridization gap with the strength of impurity scattering potential; while low energy states can only be induced in the unitary scattering limit for the weak TKI regime, where the resonance level moves universally toward the center of the hybridization gap. These impurity-induced low-energy quasiparticles will lead to characteristic signatures in scanning tunneling microscopy/spectroscopy, which has recently found success in probing into exotic properties in heavy fermion systems.
format Preprint
id arxiv_https___arxiv_org_abs_1402_6774
institution arXiv
publishDate 2014
record_format arxiv
spellingShingle Surface Local Impurity Scattering as a Probe for Topological Kondo Insulators
Wang, C. -C. Joseph
Julien, Jean-Pierre
Balatsky, A. V.
Zhu, Jian-Xin
Strongly Correlated Electrons
Shortly after the discovery of topological band insulators, topological Kondo insulators (TKIs) have also been theoretically predicted. The latter has ignited revival interest in the properties of Kondo insulators. Currently, the feasibility of topological nature in SmB$_6$ has been intensively analyzed by several complementary probes. Here by starting with a minimal-orbital Anderson lattice model, we explore the local electronic structure in a Kondo insulator. We show that the two strong topological regimes sandwiching the weak topological regime give rise to a single Dirac cone, which is located near the center or corner of the surface Brillouin zone. We further find that, when a single impurity is placed on the surface, low-energy resonance states are induced in the weak scattering limit for the strong TKI regimes and the resonance level moves monotonically across the hybridization gap with the strength of impurity scattering potential; while low energy states can only be induced in the unitary scattering limit for the weak TKI regime, where the resonance level moves universally toward the center of the hybridization gap. These impurity-induced low-energy quasiparticles will lead to characteristic signatures in scanning tunneling microscopy/spectroscopy, which has recently found success in probing into exotic properties in heavy fermion systems.
title Surface Local Impurity Scattering as a Probe for Topological Kondo Insulators
topic Strongly Correlated Electrons
url https://arxiv.org/abs/1402.6774