Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer

Toru Hirahara; Sergey V. Eremeev; Tetsuroh Shirasawa; Yuma Okuyama; Takayuki Kubo; Ryosuke Nakanishi; Ryota Akiyama; Akari Takayama; Tetsuya Hajiri; Shin Ichiro Ideta; Masaharu Matsunami; Kazuki Sumida; Koji Miyamoto; Yasumasa Takagi; Kiyohisa Tanaka; Taichi Okuda; Toshihiko Yokoyama; Shin Ichi Kimura; Shuji Hasegawa; Evgueni V. Chulkov

doi:10.1021/acs.nanolett.7b00560

Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer

Toru Hirahara^*, Sergey V. Eremeev, Tetsuroh Shirasawa, Yuma Okuyama, Takayuki Kubo, Ryosuke Nakanishi, Ryota Akiyama, Akari Takayama, Tetsuya Hajiri, Shin Ichiro Ideta, Masaharu Matsunami, Kazuki Sumida, Koji Miyamoto, Yasumasa Takagi, Kiyohisa Tanaka, Taichi Okuda, Toshihiko Yokoyama, Shin Ichi Kimura, Shuji Hasegawa, Evgueni V. Chulkov

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

109 Citations (Scopus)

Abstract

Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures. Here we have succeeded in generating a massive Dirac cone in a MnBi₂Se₄/Bi₂Se₃ heterostructure, which was fabricated by self-assembling a MnBi₂Se₄ layer on top of the Bi₂Se₃ surface as a result of the codeposition of Mn and Se. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the fabricated MnBi₂Se₄/Bi₂Se₃ heterostructure shows ferromagnetism up to room temperature and a clear Dirac cone gap opening of ∼100 meV without any other significant changes in the rest of the band structure. It can be considered as a result of the direct interaction of the surface Dirac cone and the magnetic layer rather than a magnetic proximity effect. This spontaneously formed self-assembled heterostructure with a massive Dirac spectrum, characterized by a nontrivial Chern number C = -1, has a potential to realize the QAHE at significantly higher temperatures than reported up to now and can serve as a platform for developing future "topotronics" devices.

Original language	English
Pages (from-to)	3493-3500
Number of pages	8
Journal	Nano Letters
Volume	17
Issue number	6
DOIs	https://doi.org/10.1021/acs.nanolett.7b00560
Publication status	Published - 2017 Jun 14
Externally published	Yes

Keywords

Topological insulators
magnetism
massive Dirac cone
quantum anomalous Hall effect

ASJC Scopus subject areas

Bioengineering
Chemistry(all)
Materials Science(all)
Condensed Matter Physics
Mechanical Engineering

Access to Document

10.1021/acs.nanolett.7b00560

Cite this

Hirahara, T., Eremeev, S. V., Shirasawa, T., Okuyama, Y., Kubo, T., Nakanishi, R., Akiyama, R., Takayama, A., Hajiri, T., Ideta, S. I., Matsunami, M., Sumida, K., Miyamoto, K., Takagi, Y., Tanaka, K., Okuda, T., Yokoyama, T., Kimura, S. I., Hasegawa, S., & Chulkov, E. V. (2017). Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer. Nano Letters, 17(6), 3493-3500. https://doi.org/10.1021/acs.nanolett.7b00560

Hirahara, T, Eremeev, SV, Shirasawa, T, Okuyama, Y, Kubo, T, Nakanishi, R, Akiyama, R, Takayama, A, Hajiri, T, Ideta, SI, Matsunami, M, Sumida, K, Miyamoto, K, Takagi, Y, Tanaka, K, Okuda, T, Yokoyama, T, Kimura, SI, Hasegawa, S & Chulkov, EV 2017, 'Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer', Nano Letters, vol. 17, no. 6, pp. 3493-3500. https://doi.org/10.1021/acs.nanolett.7b00560

@article{e63ac05311084742a66a1f45797e968c,

title = "Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer",

abstract = "Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures. Here we have succeeded in generating a massive Dirac cone in a MnBi2Se4/Bi2Se3 heterostructure, which was fabricated by self-assembling a MnBi2Se4 layer on top of the Bi2Se3 surface as a result of the codeposition of Mn and Se. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the fabricated MnBi2Se4/Bi2Se3 heterostructure shows ferromagnetism up to room temperature and a clear Dirac cone gap opening of ∼100 meV without any other significant changes in the rest of the band structure. It can be considered as a result of the direct interaction of the surface Dirac cone and the magnetic layer rather than a magnetic proximity effect. This spontaneously formed self-assembled heterostructure with a massive Dirac spectrum, characterized by a nontrivial Chern number C = -1, has a potential to realize the QAHE at significantly higher temperatures than reported up to now and can serve as a platform for developing future {"}topotronics{"} devices.",

keywords = "Topological insulators, magnetism, massive Dirac cone, quantum anomalous Hall effect",

author = "Toru Hirahara and Eremeev, {Sergey V.} and Tetsuroh Shirasawa and Yuma Okuyama and Takayuki Kubo and Ryosuke Nakanishi and Ryota Akiyama and Akari Takayama and Tetsuya Hajiri and Ideta, {Shin Ichiro} and Masaharu Matsunami and Kazuki Sumida and Koji Miyamoto and Yasumasa Takagi and Kiyohisa Tanaka and Taichi Okuda and Toshihiko Yokoyama and Kimura, {Shin Ichi} and Shuji Hasegawa and Chulkov, {Evgueni V.}",

note = "Funding Information: This work has been supported by Grants-In-Aid from Japan Society for the Promotion of Science (Nos. 15H05453, 16K13683, 19340078, and 23244066), the Toray Science Foundation, the Basque Country Government, Departamento de Educacion, Universidades e Investigacion (Grant No. IT-756-13), the Spanish Ministry of Science and Innovation (Grant Nos. FIS2010-19609-C02-01, FIS2013-48286-C02-02-P and FIS2013-48286-C02-01-P), the Tomsk State University Academic D.I. Mendeleev Fund Program (Grant No. 8.1.05.2015), and Saint Petersburg State University (project 15.61.202.2015). Publisher Copyright: {\textcopyright} 2017 American Chemical Society.",

year = "2017",

month = jun,

day = "14",

doi = "10.1021/acs.nanolett.7b00560",

language = "English",

volume = "17",

pages = "3493--3500",

journal = "Nano Letters",

issn = "1530-6984",

publisher = "American Chemical Society",

number = "6",

}

TY - JOUR

T1 - Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer

AU - Hirahara, Toru

AU - Eremeev, Sergey V.

AU - Shirasawa, Tetsuroh

AU - Okuyama, Yuma

AU - Kubo, Takayuki

AU - Nakanishi, Ryosuke

AU - Akiyama, Ryota

AU - Takayama, Akari

AU - Hajiri, Tetsuya

AU - Ideta, Shin Ichiro

AU - Matsunami, Masaharu

AU - Sumida, Kazuki

AU - Miyamoto, Koji

AU - Takagi, Yasumasa

AU - Tanaka, Kiyohisa

AU - Okuda, Taichi

AU - Yokoyama, Toshihiko

AU - Kimura, Shin Ichi

AU - Hasegawa, Shuji

AU - Chulkov, Evgueni V.

N1 - Funding Information: This work has been supported by Grants-In-Aid from Japan Society for the Promotion of Science (Nos. 15H05453, 16K13683, 19340078, and 23244066), the Toray Science Foundation, the Basque Country Government, Departamento de Educacion, Universidades e Investigacion (Grant No. IT-756-13), the Spanish Ministry of Science and Innovation (Grant Nos. FIS2010-19609-C02-01, FIS2013-48286-C02-02-P and FIS2013-48286-C02-01-P), the Tomsk State University Academic D.I. Mendeleev Fund Program (Grant No. 8.1.05.2015), and Saint Petersburg State University (project 15.61.202.2015). Publisher Copyright: © 2017 American Chemical Society.

PY - 2017/6/14

Y1 - 2017/6/14

N2 - Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures. Here we have succeeded in generating a massive Dirac cone in a MnBi2Se4/Bi2Se3 heterostructure, which was fabricated by self-assembling a MnBi2Se4 layer on top of the Bi2Se3 surface as a result of the codeposition of Mn and Se. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the fabricated MnBi2Se4/Bi2Se3 heterostructure shows ferromagnetism up to room temperature and a clear Dirac cone gap opening of ∼100 meV without any other significant changes in the rest of the band structure. It can be considered as a result of the direct interaction of the surface Dirac cone and the magnetic layer rather than a magnetic proximity effect. This spontaneously formed self-assembled heterostructure with a massive Dirac spectrum, characterized by a nontrivial Chern number C = -1, has a potential to realize the QAHE at significantly higher temperatures than reported up to now and can serve as a platform for developing future "topotronics" devices.

AB - Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures. Here we have succeeded in generating a massive Dirac cone in a MnBi2Se4/Bi2Se3 heterostructure, which was fabricated by self-assembling a MnBi2Se4 layer on top of the Bi2Se3 surface as a result of the codeposition of Mn and Se. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the fabricated MnBi2Se4/Bi2Se3 heterostructure shows ferromagnetism up to room temperature and a clear Dirac cone gap opening of ∼100 meV without any other significant changes in the rest of the band structure. It can be considered as a result of the direct interaction of the surface Dirac cone and the magnetic layer rather than a magnetic proximity effect. This spontaneously formed self-assembled heterostructure with a massive Dirac spectrum, characterized by a nontrivial Chern number C = -1, has a potential to realize the QAHE at significantly higher temperatures than reported up to now and can serve as a platform for developing future "topotronics" devices.

KW - Topological insulators

KW - magnetism

KW - massive Dirac cone

KW - quantum anomalous Hall effect

UR - http://www.scopus.com/inward/record.url?scp=85020770127&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85020770127&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.7b00560

DO - 10.1021/acs.nanolett.7b00560

M3 - Article

C2 - 28545300

AN - SCOPUS:85020770127

SN - 1530-6984

VL - 17

SP - 3493

EP - 3500

JO - Nano Letters

JF - Nano Letters

IS - 6

ER -

Large-Gap Magnetic Topological Heterostructure Formed by Subsurface Incorporation of a Ferromagnetic Layer

Abstract

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this