量子ホール系におけるエッジ状態とトポロジカル励起の研究

• Project Area: Topological Quantum Phenomena in Condensed Matter with Broken Symmetries
• Project/Area Number: 25103722
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Hyogo Medical University
• Principal Investigator: 福田 昭 兵庫医科大学, 医学部, 准教授 (70360633)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2014: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2013: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 量子ホール効果 / エッジ状態 / スピン拡散 / ２層系 / トポロジカル励起 / グラフェン

Outline of Annual Research Achievements

量子ホール状態、特に２次元電子系を２枚近接配置した２層系を中心に、さまざまなトンネリング・エネルギーを持つ試料でランダウ準位占有率νを変化させ、電気伝導測定やマイクロ波による共鳴現象の観測を通して、エッジ状態での電子の散乱機構とエッジの動的変化過程、および半量子渦対や磁気ロトン、スカーミオンなどの量子ホール系特有のトポロジカルな励起状態の特定とその生成・消滅機構を解明する。
本年度は、高移動度GaAs量子井戸構造試料を用いて、量子ホール領域における２次元電子系のエッジ状態のダイナミクスを明らかにすべく、動的核スピン偏極（DNP）の周波数依存性の測定及び解析を行った。その結果、DNP電流の周波数が低い直流に近い領域では、一度上昇した磁気抵抗が再び減少するという新奇な現象を発見した。このことは、エッジ状態およびドメイン構造が時間変化する中で、周波数に依存してドメインおよびエッジが分離・再結合のプロセスを複雑に繰り返していることを示唆する結果である。このことをさらに明確化するため、ホールバー構造だけでなくコルビノ構造の電極パターンを形成して試料を作成し、試験を行った。
また、同様の実験を、新奇な２次元電子系であるグラフェンを用いて行うため、単層および２層のグラフェンのデバイス化を行った。その結果、グラフェンの電気伝導度は、表面に吸着した分子吸着の効果が極めて強く、分子吸着状態でのエッジ状態やトポロジカル励起の研究が次の段階として待たれる極めて興味深い結果となった。

Research Progress Status

26年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

26年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Effect of the Inert Gas Adsorption on the Bilayer Graphene to the Localized Electron Magnetotransport (2014)
  • Author(s): A. Fukuda, D. Terasawa, Y. Ohno and K. Matsumoto
  • Journal Title: J. Phys.: Conf. Ser. Volume: 568 Issue: 5 Pages: 052009-052009
  • DOI: 10.1088/1742-6596/568/5/052009
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] High-frequency ESR measurements and ESR/NMR double resonance experiments of lightly phosphorous-doped silicon (2014)
  • Author(s): Y Fujii, S Mitsudo, K Morimoto, T Mizusaki, M Gwak, SG Lee, A Fukuda, A Matsubara, T Ueno and S Lee
  • Journal Title: J. Phys.: Conf. Ser. Volume: 568 Issue: 4 Pages: 042005-042005
  • DOI: 10.1088/1742-6596/568/4/042005
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Interlayer Diffusion of Nuclear Spin Polarization in ν= 2/3 Quantum Hall States (2014)
  • Author(s): Minh-Hai Nguyen, Shibun Tsuda, Daiju Terasawa, Akira Fukuda, Yangdong Zheng, and Anju Sawada
  • Journal Title: Physical Review B Volume: 89 Issue: 4
  • DOI: 10.1103/physrevb.89.041403
  • Peer Reviewed
• [Journal Article] Spin-Pseudospin Intertwined Excitation at ν=1 Bilayer Quantum Hall State Investigated by the Nuclear-Spin Relaxation (2013)
  • Author(s): S. Tsuda, D. Terasawa, M. H. Nguyen, A. Fukuda, Y. D. Zheng, T. Arai, A. Sawada, Z. F. Ezawa
  • Journal Title: AIP Conf. Proc. Volume: 1566 Pages: 269-270
  • DOI: 10.1063/1.4848389
  • Peer Reviewed
• [Journal Article] Interlayer Transport of the Nuclear Spin Polarization in ν=2/3 Quantum Hall States (2013)
  • Author(s): S. Tsuda, M. H. Nguyen, D. Terasawa, A. Fukuda, Y. D. Zheng, T. Arai and A. Sawada
  • Journal Title: AIP Conf. Proc. Volume: 1566 Pages: 293-294
  • DOI: 10.1063/1.4848401
  • Peer Reviewed
• [Journal Article] Nuclear spin relaxation in the SU(4) spin-pseudospin intertwined skyrmion regime in theν=1 bilayer quantum Hall state (2013)
  • Author(s): S. Tsuda, M-H. Nguyen, D. Terasawa, A. Fukuda, Z.F. Ezawa, and A. Sawada
  • Journal Title: Phys. Rev. B Volume: 88, 205103 Issue: 20 Pages: 1-4
  • DOI: 10.1103/physrevb.88.205103
  • Peer Reviewed
• [Presentation] グラフェンにおける抵抗振動と弱局在効果との関係 (2015)
  • Author(s): 寺澤大樹，福田昭，藤元章，大野恭秀，松本和彦
  • Organizer: 日本物理学会第７０回年次大会
  • Place of Presentation: 早稲田大学
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] チタンクリーニングされたグラフェンにおける弱局在効果のゲート電圧依存性と温度依存性 (2015)
  • Author(s): 藤元章，Corey Joiner，Yuxuan Jiang，寺澤大樹，福田昭，Zhigang Jiang，Eric Vogel
  • Organizer: 日本物理学会第７０回年次大会
  • Place of Presentation: 早稲田大学
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] 希薄ドープSi:Pの超低温・高周波ESR (2015)
  • Author(s): 森本和也，藤井裕，光藤誠太郎，水崎隆雄，菊池彦光，福田昭，松原明，上野智弘，山森英智，SangGap Lee，Minchan Gwak，Soonchil Lee，Sergey Vasiliev
  • Organizer: 日本物理学会第７０回年次大会
  • Place of Presentation: 早稲田大学
  • Year and Date: 2015-03-21 – 2015-03-24
• [Presentation] Low Frequency Dynamics of the Chiral Edge Domains in the Fractional Quantum Hall State (2014)
  • Author(s): A. Fukuda, S. Tsuda, D. Terasawa, A. Sawada
  • Organizer: International Conference on Topological Quantum Phenomena (TQP2014)
  • Place of Presentation: Kyoto
  • Year and Date: 2014-12-16 – 2014-12-20
• [Presentation] High-Frequency ESR Measurements of Shallow Doped Si:P at Low Temperatures and Their Extension to Lower Temperatures for High μBB/kBT (2014)
  • Author(s): K. Morimoto, Y. Fujii, S. Mitsudo, T. Mizusaki, H. Kikuchi, A. Fukuda, A. Matsubara, T. Ueno, M. Gwak, S.G. Lee, S. Lee, T. Saito and S. Vasiliev
  • Organizer: APES2014, IES and SEST2014 (APES-IES-SEST2014)
  • Place of Presentation: Nara
  • Year and Date: 2014-11-12 – 2014-11-16
• [Presentation] チタンクリーニングされたグラフェンの弱局在効果 (2014)
  • Author(s): 藤元章，Corey Joiner，Yuxuan Jiang，寺澤大樹，Tania Roy，Zohreh Razavi Hesabi，福田昭，Zhigang Jiang，Eric Vogel
  • Organizer: 日本物理学会 2014年秋季大会
  • Place of Presentation: 中部大学
  • Year and Date: 2014-09-07 – 2014-09-10
• [Presentation] Resistance maxima and deviations from the quantized Hall value induced by dynamic nuclear polarization around ν=2/3 (2014)
  • Author(s): D. Terasawa, S. Tsuda, S. Mitani, Minh Hai N., A. Fukuda and A. Sawada
  • Organizer: 32nd International Conference on the Physics of Semiconductors (ICPS 2014)
  • Place of Presentation: Austin（アメリカ）
  • Year and Date: 2014-08-10 – 2014-08-15
• [Presentation] Low Temperature Anomalies of Resistance in Titanium-Cleaned Single Layer Graphene (2014)
  • Author(s): A. Fujimoto，C. A. Joiner, Y. Jiang, T. Roy, Z. R. Hesabi, D. Terasawa, A. Fukuda, Z. Jiang, E. M. Vogel
  • Organizer: 32nd International Conference on the Physics of Semiconductors (ICPS 2014)
  • Place of Presentation: Austin（アメリカ）
  • Year and Date: 2014-08-10 – 2014-08-15
• [Presentation] Effect of the Inert Gas Adsorption on the Bilayer Graphene to the Localized Electron Magnetotransport (2014)
  • Author(s): A. Fukuda, D. Terasawa, Y. Ohno and K. Matsumoto
  • Organizer: 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: Buenos Aires（アルゼンチン）
  • Year and Date: 2014-08-06 – 2014-08-13
• [Presentation] Direct Current Nuclear Spin Polarization in the Fractional Quantum Hall Effect (2014)
  • Author(s): A. Fukuda, S. Tsuda, D. Terasawa and A. Sawada
  • Organizer: 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: Buenos Aires（アルゼンチン）
  • Year and Date: 2014-08-06 – 2014-08-13
• [Presentation] High-Frequency ESR Measurements and ESR/NMR Double Resonance Experiments of Lightly Phosporous-doped Silicon (2014)
  • Author(s): Y. Fujii, S. Mitsudo, K. Morimoto, T. Mizusaki, M. Gwak, S.G. Lee, A. Fukuda, A. Matsubara, T. Ueno and S. Lee
  • Organizer: 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: Buenos Aires（アルゼンチン）
  • Year and Date: 2014-08-06 – 2014-08-13
• [Presentation] Incompressible Motion and Enhanced Dsissipation in a Classical Two-dimensional Electron System (2014)
  • Author(s): T. Arai, S. Yamanaka, A. Sawada, A. Fukuda and H. Yayama
  • Organizer: 27th International Conference on Low Temperature Physics (LT27)
  • Place of Presentation: Buenos Aires（アルゼンチン）
  • Year and Date: 2014-08-06 – 2014-08-13
• [Presentation] 2層グラフェンの磁気抵抗値の4He吸着による変化 (2014)
  • Author(s): 寺澤大樹，福田昭，大野恭秀，松本和彦
  • Organizer: 日本物理学会 第69回年次大会
  • Place of Presentation: 東海大学
• [Presentation] Magnetotransport of the 4He-Adsorbed Bilayer Graphene (2013)
  • Author(s): A. Fukuda, D. Terasawa, Y. Ohno and K. Matsumoto
  • Organizer: 20th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-20)
  • Place of Presentation: Wroclow, Poland
• [Presentation] Transition from weak localization to strong localization regime in the bilayer graphene (2013)
  • Author(s): D. Terasawa, A. Fukuda, Y. Ohno, and K. Matsumoto
  • Organizer: 20th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-20)
  • Place of Presentation: Wroclow, Poland
• [Presentation] Current Frequency Dependence of the Resistance Enhancement in the ν = 2/3 Quantum Hall State (2013)
  • Author(s): S. Tsuda, A. Fukuda, S. Mitani , Minh Hai N., D. Terasawa and A. Sawada
  • Organizer: 20th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-20)
  • Place of Presentation: Wroclow, Poland
• [Presentation] Insulating Phase in the Dynamically Nuclear Spin Polarized ν=2/3 Quantum Hall State (2013)
  • Author(s): S. Tsuda, A. Fukuda, M. H. Nguyen, D. Terasawa and A. Sawada
  • Organizer: 20th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-20)
  • Place of Presentation: Wroclow, Poland
• [Presentation] Anomalous electric transport induced by dynamic nuclear polarization at the vicinity of ν=2/3 quantum Hall state (2013)
  • Author(s): S. Tsuda, D. Terasawa, S. Mitani, Minh Hai N., A. Fukuda, and A. Sawada
  • Organizer: 20th International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS-20)
  • Place of Presentation: Wroclow, Poland
• [Presentation] Phase Transition from Quantum Hall State to Insulator State Evoked from Nuclear Polarization by Current Pumping (2013)
  • Author(s): S. Tsuda S. Mitani, M. H. Nguyen, A. Fukuda, D. Terasawa, and A. Sawada
  • Organizer: Collaborative Conference on 3D and Materials Research (CC3DMR 2013)
  • Place of Presentation: Jeju, Korea
• [Presentation] Kosterlitz-Thouless-type pseudospin transition in the ν = 1 bilayer quantum Hall state (2013)
  • Author(s): A. Fukuda, D. Terasawa, T. Morikawa, Y. D. Zheng, and A. Sawada
  • Organizer: International Workshop for Young Researchers on Topological Quantum Phenomena in Condensed Matter with Broken Symmetries 2013
  • Place of Presentation: Ginowan
• [Presentation] Spin relaxations in SU(4) Skyrmions in the bilayer quantum Hall system (2013)
  • Author(s): D. Terasawa, S. Tsuda, A. Fukuda, and A. Sawada
  • Organizer: International Workshop for Young Researchers on Topological Quantum Phenomena in Condensed Matter with Broken Symmetries 2013
  • Place of Presentation: Ginowan
• [Presentation] 直流電流による量子ホール状態ν=2/3の状態変化 (2013)
  • Author(s): 津田是文，三谷昌平，Nguyen Minh-Hai，寺澤大樹，福田昭，澤田安樹
  • Organizer: 日本物理学会2013年秋季大会
  • Place of Presentation: 徳島大学
• [Presentation] 2層グラフェンの低温における磁気抵抗の振動と弱局在効果 (2013)
  • Author(s): 寺澤大樹，福田昭，大野恭秀，松本和彦
  • Organizer: 日本物理学会2013年秋季大会
  • Place of Presentation: 徳島大学
• [Presentation] 2層系量子ホール状態における層間核スピン輸送 (2013)
  • Author(s): Minh-Hai Nguyen、寺澤大樹、津田是文、福田昭、澤田安樹
  • Organizer: 第18回 半導体スピン工学の基礎と応用 (PASPS-18)
  • Place of Presentation: 大阪大学
• [Presentation] 量子ホール系におけるエッジ状態とトポロジカル励起の研究 (2013)
  • Author(s): 福田昭
  • Organizer: 新学術領域研究「対称性の破れた凝縮系におけるトポロジカル量子現象」第13回集中連携研究会「トポロジカル電子流体の新奇現象」
  • Place of Presentation: 岡山大学
• [Presentation] Spin relaxation of SU(4) skyrmions in the bilayer ν=1 quantum Hall states (2013)
  • Author(s): Akira Fukuda, Shibun Tsuda, Daiju Terasawa, Zyun F. Ezawa and Anju Sawada
  • Organizer: 新学術領域研究「対称性の破れた凝縮系におけるトポロジカル量子現象」第4回領域研究会
  • Place of Presentation: 名古屋大学
• [Remarks] 兵庫医科大学｜物理学
  • URL: http://www.hyo-med.ac.jp/faculty/course/physics.html
• [Remarks] 公募研究メンバー｜メンバー｜対称性の破れた凝縮系におけるトポロジカル量子現象
  • URL: http://www.topological-qp.jp/member/spmember.html
• [Remarks] 「トポロジカル量子」領域HP(日本語)
  • URL: http://www.topological-qp.jp/
• [Remarks] 「トポロジカル量子」領域HP(英語)
  • URL: http://www.topological-qp.jp/english/index.html
• [Remarks] 兵庫医科大学 物理学
  • URL: http://www.hyo-med.ac.jp/faculty/course/physics.html