Atomic scale observations of a strongly correlated topological insulator by spin and orbital resolved STM

• Project/Area Number: 19H02595
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Nagoya University (2020-2021); The University of Electro-Communications (2019)
• Principal Investigator: Miyamachi Toshio 名古屋大学, 未来材料・システム研究所, 准教授 (10437361)
• Co-Investigator(Kenkyū-buntansha): 小森 文夫 東京工業大学, 物質理工学院, 研究員 (60170388)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,680,000 (Direct Cost: ¥13,600,000、Indirect Cost: ¥4,080,000); Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2020: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2019: ¥10,140,000 (Direct Cost: ¥7,800,000、Indirect Cost: ¥2,340,000)
• Keywords: トポロジカル絶縁体 / 走査トンネル顕微鏡 / 近藤効果 / スピン / スピン偏極STM / 電子相関 / トポロジカル近藤絶縁体

Outline of Research at the Start

強い電子相関を示し、極低温で金属絶縁体転移を起こすYbB12は近年、トポロジカル近藤絶縁体として理論的に予測され、強相関電子系特有の新奇なトポロジカル量子現象の発現が期待されている。そこで、本研究では、走査トンネル顕微鏡を用いてYbB12の表面状態を３次元（面直・面内方向）に軌道・スピン分解してその起源や発現機構を原子スケールで解明し、強相関トポロジカル絶縁体を将来的なデバイス応用に繋げるための基盤研究を行う。

Outline of Final Research Achievements

We performed spin and orbital resolved STM measurements for YbB12, which is a promising candidate as a topological Kondo insulator. The purpose of this work was to understand the origin of spin-polarized surface states of YbB12 by STM in terms of electron correlations. We first optimized surface preparation conditions and realized large-area and atomically homogeneous YbB12 surface. Orbital-resolved STM observations on this surface in combination with STM Imaging of quasiparticle interference enable to discuss the roles of s, p, d, f orbitals on the emergence of metallic surface states both from real-space and momentum-space. We further performed spin polarized STM to investigate the spin polarization of YbB12 surface.

Academic Significance and Societal Importance of the Research Achievements

本研究によって、トポロジカル近藤絶縁体候補物質YbB12の金属表面状態をSTMによりスピン・電子軌道ごとに分解して評価できることが明らかになった。このことは、強相関電子系特有の新奇なトポロジカル量子現象の発現が期待される系においてSTMが新規機能性の発現機構を理解する上で強力な手法であることを示している。本研究成果によって、強相関トポロジカル絶縁体のみならず、表面数原子層の様々な電子軌道のスピンが物性を担い、かつ将来のデバイス応用が見込まれる系の新しい研究展開が期待できる。

Research Products

• [Int'l Joint Research] Karlsruhe Institute of Technology(ドイツ)
• [Journal Article] Structural and electrical characterization of the monolayer Kondo-lattice compound CePt6/Pt(111) (2021)
  • Author(s): Koichiro Ienaga, Sunghun Kim, Toshio Miyamachi, Fumio Komori
  • Journal Title: Physical Review B Volume: 104 Issue: 16 Pages: 165419-165419
  • DOI: 10.1103/physrevb.104.165419
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Resolving the spin polarization and magnetic domain wall width of (Nd,Dy)2Fe14B with spin-polarized scanning tunneling microscopy (2021)
  • Author(s): T. Miyamachi, C. Surgers, W. Wulfhekel
  • Journal Title: Applied Physics Express Volume: 14 Issue: 11 Pages: 115504-115504
  • DOI: 10.35848/1882-0786/ac2a56
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Electronic structure of 3°-twisted bilayer graphene on 4H-SiC(0001) (2021)
  • Author(s): Takushi Iimori, Anton Visikovskiy, Hitoshi Imamura, Toshio Miyamachi, Miho Kitamura, Koji Horiba, Hiroshi Kumigashira, Kazuhiko Mase, Kan Nakatsuji, Satoru Tanaka, Fumio Komori
  • Journal Title: Physical Review Materials Volume: 5 Issue: 5
  • DOI: 10.1103/physrevmaterials.5.l051001
  • Peer Reviewed
• [Journal Article] Spatial Control of Charge Doping in n-Type Topological Insulators (2021)
  • Author(s): Sakamoto Kazuyuki、Ishikawa Hirotaka、Wake Takashi、Ishimoto Chie、Fujii Jun、Bentmann Hendrik、Ohtaka Minoru、Kuroda Kenta、Inoue Natsu、Hattori Takuma、Miyamachi Toshio、Komori Fumio、Yamamoto Isamu、Fan Cheng、Kr?ger Peter、Ota Hiroshi、Matsui Fumihiko、Reinert Friedrich、Avila Jos?、Asensio Maria C.
  • Journal Title: Nano Letters Volume: 21 Issue: 10 Pages: 4415-4422
  • DOI: 10.1021/acs.nanolett.1c01100
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Odd spin frustration in Cr(001) films thinner than three nanometers revealed by spin-polarized scanning tunneling microscopy (2021)
  • Author(s): T. Kawagoe, R. Oka, T. Miyamachi, S. Suga
  • Journal Title: PHYSICAL REVIEW B Volume: 103 Issue: 8 Pages: 085427-085427
  • DOI: 10.1103/physrevb.103.085427
  • Peer Reviewed
• [Journal Article] Subatomic Distortion of Surface Monolayer Lattice Visualized by Moire Pattern (2021)
  • Author(s): T. Hattori, N. Kawamura, T. Iimori, T. Miyamachi, F. Komori
  • Journal Title: Nano Letters Volume: 6 Issue: 6 Pages: 2406-2406
  • DOI: 10.1021/acs.nanolett.0c04408
  • Peer Reviewed
• [Journal Article] Realizing large out-of-plane magnetic anisotropy in L10-FeNi films grown by nitrogen- surfactant epitaxy on Cu(001) (2020)
  • Author(s): K. Kawaguchi, T. Miyamachi, T. Iimori, Y. Takahashi, T. Hattori, T. Yokoyama, M. Kotsugi, F. Komori
  • Journal Title: PHYSICAL REVIEW MATERIALS Volume: 4 Issue: 5 Pages: 054403-054403
  • DOI: 10.1103/physrevmaterials.4.054403
  • Peer Reviewed
• [Journal Article] Twisted bilayer graphene fabricated by direct bonding in a high vacuum (2020)
  • Author(s): Hitoshi Imamura, Anton Visikovskiy, Ryosuke Uotani, Takashi Kajiwara, Hiroshi Ando, Takushi Iimori, Kota Iwata, Toshio Miyamachi, Kan Nakatsuji, Kazuhiko Mase, Tetsuroh Shirasawa, Fumio Komori, Satoru Tanaka
  • Journal Title: Applied Physics Express Volume: 13 Issue: 7 Pages: 075004-075004
  • DOI: 10.35848/1882-0786/ab99d1
  • Peer Reviewed
• [Journal Article] Hexagonal iron nitride monolayer on Cu (001): zigzag-line-in-trough alignment (2020)
  • Author(s): M. Yamada, K. Ienaga, Y. Takahashi, T. Miyamachi, and F. Komori
  • Journal Title: Surface Science Volume: 700 Pages: 121679-121679
  • DOI: 10.1016/j.susc.2020.121679
  • Peer Reviewed
• [Journal Article] Sensing surface lattice strain with Kondo resonance of single Co adatom (2020)
  • Author(s): Iwata Kota、Miyamachi Toshio、Minamitani Emi、Komori Fumio
  • Journal Title: Applied Physics Letters Volume: 116 Issue: 5 Pages: 051604-051604
  • DOI: 10.1063/1.5142064
  • Peer Reviewed
• [Journal Article] Electronic and magnetic properties of the Fe2N monolayer film tuned by substrate symmetry (2019)
  • Author(s): Hattori Takuma、Miyamachi Toshio、Yokoyama Toshihiko、Komori Fumio
  • Journal Title: Journal of Physics: Condensed Matter Volume: 31 Issue: 25 Pages: 255001-255001
  • DOI: 10.1088/1361-648x/ab0fbc
  • Peer Reviewed
• [Journal Article] Fabrication of L10-type FeCo ordered structure using a periodic Ni buffer layer (2019)
  • Author(s): Ito Hisaaki、Saito Masahiro、Miyamachi Toshio、Komori Fumio、Koganezawa Tomoyuki、Mizuguchi Masaki、Kotsugi Masato
  • Journal Title: AIP Advances Volume: 9 Issue: 4 Pages: 045307-045307
  • DOI: 10.1063/1.5079982
  • Peer Reviewed / Open Access
• [Presentation] Pt(111)上のCePt2単原子層の成長と電子状態 (2022)
  • Author(s): 家永紘一郎, 金聖憲, 宮町俊生, 加藤弘一, 小森文夫
  • Organizer: 日本物理学会 第77回年次大会
• [Presentation] SiC基板上の1度以下のツイスト2層グラフェンの電子状態 (2022)
  • Author(s): 飯盛拓嗣, 今村均, 宮町俊生, 中辻寛, 北村未歩, 堀場弘司, 間瀬一彦, Visikovskiy Anton, 田中悟, 小森文夫
  • Organizer: 日本物理学会 第77回年次大会
• [Presentation] スピン偏極STMによるNdFeB磁石の磁壁幅の実空間・高分解能観察 (2022)
  • Author(s): 宮町俊生, Wulf Wulfhekel
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] CoPc/γ'-Fe4N 有機－無機ハイブリッド薄膜の界面磁気状態 (2022)
  • Author(s): 小野広喜, 梅田佳孝, 山本航平, 石山修, 横山利彦, 水口将輝, 宮町俊生
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] 窒素サーファクタント効果により作製した L10-FeCo 規則合金薄膜の界面磁気結合状態の制御 (2022)
  • Author(s): 梅田佳孝, 小野広喜, 山本航平, 石山修, 横山利彦, 水口将輝, 宮町俊生
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] Anomalous Nernst effect in Co/Au/Fe trilayer thin films (2022)
  • Author(s): Hiroki Fukuda, Toshio Miyamachi, Masaki Mizuguchi
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] Anomalous Nernst and Hall effects in Ge-doped Co thin films (2022)
  • Author(s): Takuya Tsujimoto, Toshio Miyamachi, Masaki Mizuguchi
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] 3nm厚のCr(001)薄膜で観測された特異なスピンフラストレーション (2021)
  • Author(s): 川越毅, 宮町俊生, 菅滋正
  • Organizer: 日本物理学会 2021年秋季大会
• [Presentation] 走査トンネル顕微分光を用いた2次元近藤格子CePt6/Pt(111)の電子状態観測 (2021)
  • Author(s): 家永紘一郎, 金聖憲, 宮町俊生, 小森文夫
  • Organizer: 日本物理学会 2021年秋季大会
• [Presentation] 大面積数度ツイストグラフェンの電子状態 (2021)
  • Author(s): 飯盛拓嗣, 今村均, 宮町俊生, 服部琢磨, 中辻寛, 北村未歩, 堀場弘司, 間瀬一彦, Visikovskiy Anton, 田中悟, 小森文夫
  • Organizer: 日本物理学会 2021年秋季大会
• [Presentation] 単層近藤格子CePt2/Pt(111)の構造と電子状態 (2021)
  • Author(s): 家永紘一郎, 金聖憲, 宮町俊生, 小森文夫
  • Organizer: 日本物理学会 2021年秋季大会
• [Presentation] Resolving the spin polarization and magnetic domain wall width of (Nd, Dy)2Fe14B with spin-polarized scanning tunneling microscopy (2021)
  • Author(s): Toshio Miyamachi, Wulf Wulfhekel
  • Organizer: ICMaSS2021
  • Int'l Joint Research
• [Presentation] Challenges in the application of spin-polarized STM to materials science (2021)
  • Author(s): Toshio Miyamachi
  • Organizer: The 29th International Colloquium on Scanning Probe Microscopy
  • Int'l Joint Research / Invited
• [Presentation] 窒素サーファクタント効果により作製したFeCo合金超薄膜の構造と磁気状態 (2021)
  • Author(s): 宮町俊生, 高橋優樹, 飯盛拓嗣, 服部卓磨, 山本航平, 小板谷貴典, 横山利彦, 小嗣真人, 小森文夫
  • Organizer: 日本物理学会第76回年次大会
• [Presentation] スピン偏極 STM と放射光 X 線磁気円二色性測定による 磁性超薄膜ヘテロ構造の原子スケール表面・界面磁性研究 (2021)
  • Author(s): 宮町俊生
  • Organizer: Nanospec2021
  • Invited
• [Presentation] 構造制御されたSmB6(001)表面の金属的な電子状態 (2020)
  • Author(s): 宮町俊生, 菅滋正, 飯盛拓嗣, 伊賀文俊, 小森文夫
  • Organizer: 日本物理学会2020年秋季大会
• [Presentation] SiC(0001)上のツイストグラフェンの電子状態のツイスト角度依存性 (2020)
  • Author(s): 飯盛拓嗣, 今村均, 魚谷亮介, 宮町俊生, 服部琢磨, 中辻寛, 北村未歩, 堀場弘司, 間瀬一彦, 梶原隆司, Visikovskiy Anton, 田中悟, 小森文夫
  • Organizer: 日本物理学会2020年秋季大会
• [Presentation] SmB6(001)表面の構造安定性と表面電子状態 (2020)
  • Author(s): 宮町俊生, 菅滋正, 飯盛拓嗣, Martin Ellguth, Christian Tusche, Claus M. Schneider, 伊賀文俊, 小森文夫
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] SiC(0001)上のツイストグラフェンの電子状態について II (2020)
  • Author(s): 飯盛拓嗣, 今村均, 魚谷亮介, 宮町俊生, 服部琢磨, 中辻寛, 間瀬一彦, 梶原隆司, Visikovskiy Anton, 田中悟, 小森文夫
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] 走査トンネル顕微鏡によるCu(111)基板上における三角格子窒化鉄膜のひずみ観察 (2020)
  • Author(s): 服部卓磨, 飯盛拓嗣, 河村紀一, 宮町俊生, 小森文夫
  • Organizer: 日本物理学会第75回年次大会
• [Presentation] 水素修飾による窒化銅表面上のCo単一原子のスピン状態変化 (2019)
  • Author(s): 宮町俊生, Thomas Gozlinski, Wulf Wulfhekel, 小森文夫
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Cu(001)表面上Co単原子の近藤効果のCu格子の歪みに対する応答のSTM測定 (2019)
  • Author(s): 岩田孝太, 宮町俊生, 南谷英美, 小森文夫
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] SiC(0001)上のツイストグラフェンの電子状態について (2019)
  • Author(s): 飯盛拓嗣, 今村均, 魚谷亮介, 宮町俊生, 中辻寛, 間瀬一彦, 梶原隆司, Visikovskiy Anton, 田中悟, 小森文夫
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Cu(001)基板上の窒化コバルト鉄膜の作製と構造評価 (2019)
  • Author(s): 服部卓磨, 飯盛拓嗣, 宮町俊生, 小森文夫
  • Organizer: 日本物理学会2019年秋季大会
• [Presentation] Magnetic anisotropy of L10-FeNi fabricated by N- surfactant epitaxy (2019)
  • Author(s): Toshio Miyamachi, Kaishu Kawaguchi, Takushi Iimori, Yuki Takahashi, Takuma Hattori, Toshihiko Yokoyama, Masato Kotsugi, Fumio Komori
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research
• [Presentation] Physical properties of Fe2N monolayers tuned by Cu substrates (2019)
  • Author(s): T. Hattori, T. Iimori, T. Miyamachi, T. Yokoyama, F. Komori
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research
• [Presentation] Study of fabrication method of L10-FeCo (2019)
  • Author(s): Hisaaki Ito, Takuya Miyashita, Takuya Kumagai, Toshio Miyamachi, Fumio Komori, Tomoyuki Koganezawa, Takuo Ohkochi, Masato Kotsugi
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research
• [Presentation] Atomic scale surface and interface magnetism of Mn/Fe thin film heterostructures (2019)
  • Author(s): T. Miyamachi, S. Nakashima, Y. Takagi, T. Yokoyama, F. Komori
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research
• [Presentation] Fabrication FeNi thin films on Al2O3(0001) (2019)
  • Author(s): Takuya Miyashita, Hisaaki Ito, Takuya Kumagai, Tomoyuki Koganezawa, Toshio Miyamachi, Fumio Komori, Masato Kotsugi
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research
• [Presentation] Toward fabrication of L10-FeCo thin films using the nitrogen surfactant effect (2019)
  • Author(s): Yuki Takahashi, Toshio Miyamachi, Takushi Iimori, Takuma Hattori, Takanori Koitaya, Kohei Yamamoto, Toshihiko Yokoyama, Masato Kotsugi, Fumio Komori
  • Organizer: 19th International Conference on Solid Films and Surfaces
  • Int'l Joint Research