Interfacial structure control for domain wall memories with low-power consumption

• Project/Area Number: 20H02196
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Ibaraki University
• Principal Investigator: 小峰 啓史 茨城大学, 理工学研究科(工学野), 准教授 (90361287)
• Co-Investigator(Kenkyū-buntansha): 青野 友祐 茨城大学, 理工学研究科(工学野), 教授 (20322662) ; 長谷川 靖洋 埼玉大学, 理工学研究科, 准教授 (60334158) ; 千葉 貴裕 東北大学, 学際科学フロンティア研究所, 助教 (90803297)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000); Fiscal Year 2023: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2022: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2021: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2020: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000)
• Keywords: トポロジカル絶縁体 / スピン軌道トルク / 磁気異方性 / 界面制御 / 電界制御 / 磁気メモリ / 低消費電力 / 磁壁移動型メモリ / 低電力動作 / 磁性絶縁体 / ダンピング定数の電界制御 / スピン波情報処理 / 閾値電流 / 磁気トポロジカル絶縁体 / 磁気異方性の電界制御 / FET型メモリ素子

Outline of Research at the Start

磁壁移動型メモリ実現のためには，低消費電力・高速動作を両立する必要があり，スピン軌道トルクの積極的な利用に加えて，磁壁ピニングを抑制する構造上の工夫が必要である．本研究では，電荷-スピン変換を磁壁に効率よく伝達するため，トポロジカル絶縁体と磁性体の界面状態を理解する．磁性層/トポロジカル絶縁層界面の電子状態解析，及び，異常ホール抵抗のハーモニック解析を通じて，大きな界面スピン軌道トルクを誘起するための材料および界面制御方法を探索する．低電流駆動およびロバストネス向上のため，磁壁ピニング効果を抑制するための軟磁性被覆構造も併行して検討し，低消費電力・高速動作を両立する基本原理を明らかにする．

Outline of Annual Research Achievements

本研究では，低消費電力・高速動作を両立するスピントロニクスデバイスを目指し、界面におけるスピン軌道トルクの積極的に利用した新しい素子構造を検討した。電荷-スピン変換を磁壁に効率よく伝達するため，ビスマス系化合物，特にトポロジカル絶縁体と磁性体の界面状態を目指した。磁性層/トポロジカル絶縁層界面の電子状態解析，及び，異常ホール抵抗測定を通じて、界面電子状態を調べたところ、狭いdバンドがフェルミ面にかかることから、トポロジカル絶縁体の界面状態を有効活用出来ないことがわかった。一方で、磁性絶縁体とトポロジカル絶縁体の接合による界面状態を電圧制御することで、界面おける大きなスピン軌道トルクを誘起することが可能である。さらに、界面状態のスピン-運動量ロッキングを使うと、電圧により磁気異方性が制御出来る可能性を明らかにした。つまり、ゲート電圧印加によって磁気異方性およびスピン軌道トルクの同時制御が可能となる。このような磁気トポロジカル絶縁体素子を提案し、電圧による磁化反転を解析したところ、磁気トンネル接合よりも低電力(1V未満)で動作可能であり、消費電力が低いスピントロニクスデバイスの可能性(0.1fJ/bit未満)を示唆した。加えて、熱揺らぎがある下での磁化反転シミュレーションを行い、実用化に重要な書き込みエラー率を調べたところ、100nmスケール素子において実用に十分な書き込みエラー率が実現出来る可能性を明らかにした。

Research Progress Status

令和5年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和5年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Universidad Tecnologica Metropolitana(チリ)
• [Int'l Joint Research] Universidad tecnolo'gica metropolitana(チリ)
• [Journal Article] Ultrastrong-coupled magnon?polariton in a dynamical inductor based on magnetic-insulator/topological-insulator bilayers (2024)
  • Author(s): Chiba Takahiro、Komine Takashi、Aono Tomosuke
  • Journal Title: Applied Physics Letters Volume: 124 Issue: 1 Pages: 012402-012402
  • DOI: 10.1063/5.0173898
  • Peer Reviewed
• [Journal Article] Fully micromagnetic analysis of voltage-controlled magnetization switching in magnetic-topological-insulator-based devices (2024)
  • Author(s): Komine Takashi、Chiba Takahiro
  • Journal Title: AIP Advances Volume: 14 Issue: 2 Pages: 025132-025132
  • DOI: 10.1063/9.0000798
  • Peer Reviewed / Open Access
• [Journal Article] Composition dependence of anomalous Nernst effect in amorphous TbFeCo thin films with perpendicular magnetic anisotropy (2024)
  • Author(s): Ando Ryo、Komine Takashi
  • Journal Title: Journal of Applied Physics Volume: 135 Issue: 9 Pages: 093906-093906
  • DOI: 10.1063/5.0189969
  • Peer Reviewed / Open Access
• [Journal Article] Magnetic printing characteristics of burst signals by using double magnet master media (2024)
  • Author(s): Komine Takashi
  • Journal Title: AIP Advances Volume: 14 Issue: 3 Pages: 035138-035138
  • DOI: 10.1063/9.0000792
  • Peer Reviewed / Open Access
• [Journal Article] Combinatorial dependence of magnetic printing characteristics in double magnet master media for energy-assisted magnetic recording (2023)
  • Author(s): Komine Takashi
  • Journal Title: AIP Advances Volume: 13 Issue: 2 Pages: 025310-025310
  • DOI: 10.1063/9.0000480
  • Peer Reviewed / Open Access
• [Journal Article] Temperature profile of the Thomson-effect-induced heat release/absorption in junctionless single conductors (2023)
  • Author(s): Chiba Takahiro、Iguchi Ryo、Komine Takashi、Hasegawa Yasuhiro、Uchida Ken-ichi
  • Journal Title: Japanese Journal of Applied Physics Volume: 62 Issue: 3 Pages: 037001-037001
  • DOI: 10.35848/1347-4065/acc3e6
  • Peer Reviewed
• [Journal Article] Numerical analysis of voltage-controlled magnetization switching operation in magnetic-topological-insulator-based devices (2023)
  • Author(s): Komine Takashi、Chiba Takahiro
  • Journal Title: Applied Physics Letters Volume: 123 Issue: 10 Pages: 102404-102404
  • DOI: 10.1063/5.0162297
  • Peer Reviewed
• [Journal Article] Master Structure Dependence of Double Magnet Master on Performance of Magnetic Printing Onto Energy-Assisted Magnetic Recording Media (2022)
  • Author(s): Komine Takashi
  • Journal Title: IEEE Transactions on Magnetics Volume: 58 Issue: 8 Pages: 1-5
  • DOI: 10.1109/tmag.2022.3147910
  • Peer Reviewed
• [Journal Article] Room-temperature magnetoresistance in Ni78Fe22/C8-BTBT/Ni78Fe22 nanojunctions fabricated from magnetic thin-film edges using a novel technique (2022)
  • Author(s): Matsuzaka Mizuki、Sasaki Yuma、Hayashi Kyohei、Misawa Takahiro、Komine Takashi、Akutagawa Tomoyuki、Fujioka Masaya、Nishii Junji、Kaiju Hideo
  • Journal Title: Nanoscale Advances Volume: 4 Issue: 22 Pages: 4739-4747
  • DOI: 10.1039/d2na00442a
  • Peer Reviewed / Open Access
• [Journal Article] Double Magnet Master Media for Magnetic Printing Onto Energy-Assisted Magnetic Recording Media (2022)
  • Author(s): Komine Takashi
  • Journal Title: IEEE Transactions on Magnetics Volume: 58 Issue: 2 Pages: 1-5
  • DOI: 10.1109/tmag.2021.3082515
  • Peer Reviewed
• [Journal Article] A Novel Technique for Controlling Anisotropic Ion Diffusion: Bulk Single‐Crystalline Metallic Silicon Clathrate (2022)
  • Author(s): Iwasaki Suguru、Morito Haruhiko、Komine Takashi、Morita Kazuki、Shibuya Taizo、Nishii Junji、Fujioka Masaya
  • Journal Title: Advanced Materials Volume: 34 Issue: 9 Pages: 2106754-2106754
  • DOI: 10.1002/adma.202106754
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Voltage-control of damping constant in magnetic-insulator/topological-insulator bilayers (2021)
  • Author(s): Chiba Takahiro、Leon Alejandro O.、Komine Takashi
  • Journal Title: Applied Physics Letters Volume: 118 Issue: 25 Pages: 252402-252402
  • DOI: 10.1063/5.0046217
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Elemental Topological Dirac Semimetal α‐Sn with High Quantum Mobility (2021)
  • Author(s): Anh Le Duc、Takase Kengo、Chiba Takahiro、Kota Yohei、Takiguchi Kosuke、Tanaka Masaaki
  • Journal Title: Advanced Materials Volume: 33 Issue: 51 Pages: 2104645-2104645
  • DOI: 10.1002/adma.202104645
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Voltage-Driven Magnetization Switching via Dirac Magnetic Anisotropy and Spin-Orbit Torque in Topological-Insulator-Based Magnetic Heterostructures (2020)
  • Author(s): Chiba Takahiro、Komine Takashi
  • Journal Title: Physical Review Applied Volume: 14 Issue: 3
  • DOI: 10.1103/physrevapplied.14.034031
  • Peer Reviewed
• [Journal Article] Thermoelectric refrigerator based on asymmetric surfaces of a magnetic topological insulator (2020)
  • Author(s): Chiba Takahiro、Komine Takashi
  • Journal Title: AIP Advances Volume: 10 Issue: 12 Pages: 125230-125230
  • DOI: 10.1063/9.0000005
  • Peer Reviewed / Open Access
• [Presentation] Write-error rate estimation of voltage-controlled magnetization switching in a magnetic-topological-insulator-based device (2023)
  • Author(s): T. Komine, S. Watahiki, and T. Chiba
  • Organizer: 2023 Intermag Conference
  • Int'l Joint Research
• [Presentation] TbFeCo磁性薄膜の異常ネルンスト効果に寄与する因子分析 (2023)
  • Author(s): 安藤亮，小峰啓史
  • Organizer: 第84回 応用物理学会秋季学術講演会
• [Presentation] トポロジカル絶縁体/磁性絶縁体二層膜における強結合磁気共鳴 (2023)
  • Author(s): 千葉貴弘，小峰啓史，青野友祐
  • Organizer: 第47回 日本磁気学会学術講演会
• [Presentation] アモルファスTbFeCo 磁性薄膜における熱電テンソルの組成依存性 (2023)
  • Author(s): 小峰啓史，安藤亮
  • Organizer: 第47回 日本磁気学会学術講演会
• [Presentation] ダブルマグネット型マスター媒体によるバースト信号の転写特性 (2023)
  • Author(s): 小峰啓史
  • Organizer: 第47回 日本磁気学会学術講演会
• [Presentation] Voltage-control of magnetization dynamics by using topological insulators (2023)
  • Author(s): T. Komine, and T. Chiba
  • Organizer: 第47回 日本磁気学会学術講演会 / Symposium on "Advanced local probe techniques in nanoscaled magnetism"
  • Invited
• [Presentation] Numerical analysis of write-error-rate in magnetic-topological-insulator-based devices with voltage-controlled magnetization switching (2023)
  • Author(s): T. Komine, and T. Chiba
  • Organizer: The 68th Annual Magnetism and Magnetic Materials (MMM) Conference
  • Int'l Joint Research
• [Presentation] Magnetic printing characteristics of burst signals by using double magnet mater media (2023)
  • Author(s): T. Komine
  • Organizer: The 68th Annual Magnetism and Magnetic Materials (MMM) Conference
  • Int'l Joint Research
• [Presentation] 磁性トポロジカル絶縁体素子の電圧制御磁化反転における書き込みエラー率の数値解析 (2023)
  • Author(s): 小峰啓史，綿引詩門，千葉貴裕
  • Organizer: 第70回 応用物理学会春季学術講演会
• [Presentation] Observation of magnetoresistance in Ni78Fe22/C8-BTBT/Ni78Fe22 nanojunctions at room temperature (2022)
  • Author(s): M. Matsuzaka, Y. Sasaki, K. Hayashi, T. Misawa, T. Komine, T. Akutagawa, M. Fujioka, J. Nishii, H. Kaiju
  • Organizer: 第83回 応用物理学会秋季学術講演会
• [Presentation] Type-II Na-Siクラスレートにおける Naイオンの拡散機構解明 (2022)
  • Author(s): 岩﨑秀，小峰啓史，森田一軌，澁谷泰蔵，森戸春彦，藤岡正弥
  • Organizer: 2022年秋期講演大会
• [Presentation] Room-temperature magnetoresistance in Ni78Fe22/C8-BTBT/Ni78Fe22 nanojunctions fabricated using magnetic thin-film edges (2022)
  • Author(s): M. Matsuzaka, Y. Sasaki, K. Hayashi, T. Misawa, T. Komine, T. Akutagawa, M. Fujioka, J. Nishii, H. Kaiju
  • Organizer: 35th International Microprocesses and Nanotechnology Conference
  • Int'l Joint Research
• [Presentation] Combination dependence of printing characteristics in double magnet master media for energy-assisted magnetic recording (2022)
  • Author(s): T. Komine
  • Organizer: The 67th Annual Magnetism and Magnetic Materials (MMM) Conference
  • Int'l Joint Research
• [Presentation] トポロジカル絶縁体を活用した磁化ダイナミクスの電圧制御とその応用 (2022)
  • Author(s): 千葉貴裕，アレハンドロ・レオン，小峰啓史
  • Organizer: 第240回研究会／第95回ナノマグネティックス専門研究会 「磁気物性に関する計算科学の最前線」
  • Invited
• [Presentation] Observation of spin signal in molecular nanojunctions utilizing magnetic thin-film edges at room temperature (2022)
  • Author(s): M. Matsuzaka, Y. Sasaki, K. Hayashi, T. Misawa, T. Komine, T. Akutagawa, M. Fujioka, J. Nishii, H. Kaiju
  • Organizer: The 23rd RIES-Hokudai International Symposium
  • Int'l Joint Research
• [Presentation] Voltage-control of magnetic properties in topological-insulator/magnetic-insulator bilayers (2022)
  • Author(s): T. Chiba, A. O. Leon, T. Komine
  • Organizer: 2022 Joint MMM-Intermag Conference
  • Int'l Joint Research / Invited
• [Presentation] Master structure dependence of double magnet master on magnetic printing performance onto energy-assisted magnetic recording media (2022)
  • Author(s): T. Komine
  • Organizer: 2022 Joint MMM-Intermag Conference
  • Int'l Joint Research
• [Presentation] Double magnet master media for magnetic printing onto energy-assisted magnetic recording media (2021)
  • Author(s): T. Komine
  • Organizer: INTERMAG 2021
  • Int'l Joint Research
• [Presentation] ダブルマグネット型マスター媒体による磁気転写特性のマスター構造依存性 (2021)
  • Author(s): 小峰啓史
  • Organizer: 第45回日本磁気学会学術講演会
• [Presentation] Voltage-Control of Magnetization Dynamics in Topological-insulator-based Magnetic Heterostructures (2021)
  • Author(s): T. Chiba, Alejandro O. Leon, T. Komine
  • Organizer: Joint Conference: 24th International Conference on Electronic Properties of Two-Dimensional Systems / 20th International Conference on Modulated Semiconductor Structures
  • Int'l Joint Research
• [Presentation] Voltage-Control of Magnetization Dynamics in Topological-insulator-based Magnetic Heterostructures (2021)
  • Author(s): T. Chiba, A. O. Leon, T. Komine
  • Organizer: 26th Physics and Applications of Spin-related Phenomena in Semiconductors
  • Int'l Joint Research
• [Presentation] Ambipolar Seebeck power generator based on asymmetric surfaces of magnetic topological insulators (2020)
  • Author(s): T. Chiba, S. Takahashi, T. Komine
  • Organizer: The 65th Annual Magnetism and Magnetic Materials
  • Int'l Joint Research
• [Presentation] Voltage-control of Spin-Orbit Torque and Magnetic Anisotropy in Topological Insulator Heterostructures (2020)
  • Author(s): T. Chiba, T. Komine
  • Organizer: The 65th Annual Magnetism and Magnetic Materials
  • Int'l Joint Research
• [Presentation] Spin Transport Properties in Ni78Fe22/Mq3 (M=Al, Er)/Ni78Fe22 Nanoscale Junction Devices Utilizing Magnetic Thin-Film Edges (2020)
  • Author(s): . Senshu, Y. Sasaki, Y. Nakayama, T. Misawa, T. Komine, N. Hoshino, T. Akutagawa, M. Fujioka, J. Nishii and H. Kaiju
  • Organizer: 33rd International Microprocesses and Nanotechnology Conference
  • Int'l Joint Research
• [Presentation] Ni78Fe22/Mq3(M = Al, Er)/Ni78Fe22 ナノ接合素子における室温磁気抵抗効果 (2020)
  • Author(s): 千秋賀英子，佐々木悠馬，中山雄介，三澤貴浩，小峰啓史，星野哲久， 芥川智行，藤岡正弥，西井準治，海住英生
  • Organizer: 第44回 日本磁気学会学術講演会
• [Presentation] 界面ディラック電子に起因した磁気異方性に基づく電圧制御磁化反転 (2020)
  • Author(s): 千葉貴裕，小峰啓史
  • Organizer: 第68回 応用物理学会春季学術講演会
• [Remarks] 新機能性材料研究室
  • URL: http://dirac.dmt.ibaraki.ac.jp