Updated on 2025/03/03

写真a

 
Takahiro Moriyama
 
Organization
Graduate School of Engineering Materials Physics 1 Professor
Graduate School
Graduate School of Engineering
Undergraduate School
School of Engineering Physical Science and Engineering
Title
Professor

Degree 3

  1. Ph.D. (Physics) ( 2008.8   University of Delware ) 

  2. M. Eng. ( 2003.3   Tohoku University ) 

  3. B.S. ( 2001.3   Tohoku University ) 

Research Interests 6

  1. THz spintronics

  2. Spintronics

  3. Antiferromagnets

  4. Magnetism

  5. Magneto-optics

  6. High frequency measurements

Research Areas 2

  1. Nanotechnology/Materials / Applied physical properties  / spintronics

  2. Natural Science / Magnetism, superconductivity and strongly correlated systems  / magnetism

Research History 6

  1. Nagoya University   Graduate School of Engineering Materials Physics   Professor

    2023.4

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    Country:Japan

  2. Kyoto University   Institute for Chemical Research   Associate Professor

    2016.4 - 2023.3

  3. National Institute for Standards and Technology (USA)   Guest Researcher

    2014.9 - 2014.12

  4. Kyoto University   Institute for Chemical Research   Assistant Professor

    2012.8 - 2016.3

  5. TDK-Headway Technologies,Inc. (USA)   R&D   Sr. Characterization Engineer

    2011.11 - 2012.8

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Education 3

  1. University of Delaware   Art and Science   Department of Physics, Ph.D.

    2003.9 - 2008.8

  2. Tohoku University   Graduate school of Engineering   Materials Science, M. Eng.

    2001.4 - 2003.3

  3. Tohoku University   Engineering department   Materials Science, B.S.

    1997.4 - 2001.3

Professional Memberships 3

  1. American Physical Society

  2. THE JAPAN SOCIETY OF APPLIED PHYSICS

  3. THE MAGNETICS SOCIETY OF JAPAN

Committee Memberships 8

  1. IEEE magnetic society   Advisory Comittee Member  

    2022.12 - 2025.12   

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    Committee type:Academic society

  2. The Japan Society of Appiled Physics, Spintronics division   General Comittee Member  

    2021.3   

  3. The Japan Society of Appiled Physics   Secretary  

    2019.3   

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    Committee type:Academic society

  4. The Japan Society of Appiled Physics, Spintronics division   Secretary  

    2019.3 - 2021.2   

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    Committee type:Academic society

  5. New Journal of Physics   Editorial board member  

    2018.3   

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    Committee type:Academic society

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Awards 3

  1. Contribution Award

    2020.9   The magnetic society of Japan   Contribution to the 43rd annual conference in magnetics in Japan

  2. Best Papar Award

    The magnetic society of Japan   Magnetoresistance in Bilayer of Heavy Metal and Non-collinear Antiferromagnet

    Takahiro Moriyama

  3. Scholastic Excellence Named In Dean's List

    University of Delaware  

    Takahiro Moriyama

 

Papers 188

  1. Inter- and Intrasublattice Spin Mixing Conductance of the Antiferromagnetic Spin Pumping Effect in α-Fe2O3/Pt

    T. Hattori, A. Fukuoka, K. Kawagita, K. Tada, Y. Ishikawa, Y. Yamaguchi, Y. Tatematsu, Y. Fujii, M. Kimata, S. Kimura, D. Kan, J. Ohe, T. Moriyama

    Physical Review Letters   Vol. 133 ( 25 ) page: 256701   2024.12

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    Language:English   Publishing type:Research paper (scientific journal)  

    The spin pumping effect in antiferromagnets, which ultimately converts THz waves into a spin current, is the key physical mechanism leading to an essential function which harnesses the THz technology and spintronics. Here, we report thorough experimental investigations of the spin current induced by the antiferromagnetic spin pumping effect in epitaxial α-Fe2O3 thin films having two distinct dynamic modes and unambiguously show that both the inter- and intrasublattice spin mixing conductance are equally substantial. Our experimental insight is an important advance for understanding the physics of transduction between the spin current and the staggered magnetization dynamics at THz frequency.

    DOI: 10.1103/PhysRevLett.133.256701

    Scopus

    PubMed

  2. Giant gate modulation of antiferromagnetic spin reversal by the magnetoelectric effect

    Kakeru Ujimoto, Hiroki Sameshima, Kentaro Toyoki, Takahiro Moriyama, Kohji Nakamura, Yoshinori Kotani, Motohiro Suzuki, Ion Iino, Naomi Kawamura, Ryoichi Nakatani, Yu Shiratsuchi

    NPG Asia Materials   Vol. 16 ( 1 )   2024.12

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    Publishing type:Research paper (scientific journal)  

    In this study, using the Pt/Cr2O3/Pt epitaxial trilayer, we demonstrate the giant voltage modulation of the antiferromagnetic spin reversal and the voltage-induced 180° switching of the Néel vector in maintaining a permanent magnetic field. We obtained a significant modulation efficiency of the switching field, Δμ0HSW/ΔV (Δμ0HSW/ΔE), reaching a maximum of −500 mT/V (−4.80 T nm/V); this value was more than 50 times greater than that of the ferromagnetic-based counterparts. From the temperature dependence of the modulation efficiency, X-ray magnetic circular dichroism measurements and first-principles calculations, we showed that the origin of the giant modulation efficiency relied on the electric field modulation of the net magnetization due to the magnetoelectric effect. From the first-principles calculation and the thickness effect on the offset electric field, we found that the interfacial magnetoelectric effect emerged. Our demonstration reveals the energy-efficient and widely applicable operation of an antiferromagnetic spin based on a mechanism distinct from magnetic anisotropy control.

    DOI: 10.1038/s41427-024-00541-z

    Scopus

  3. Handedness manipulation of propagating antiferromagnetic magnons

    Yoichi Shiota, Tomohiro Taniguchi, Daiju Hayashi, Hideki Narita, Shutaro Karube, Ryusuke Hisatomi, Takahiro Moriyama, Teruo Ono

    Nature Communications   Vol. 15 ( 1 ) page: 9750   2024.11

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/s41467-024-54125-0

    Web of Science

    Scopus

    PubMed

  4. Magneto-optical Kerr effect of noncollinear antiferromagnetic Mn<inf>3</inf>Ir films

    Kihiro T. Yamada, Kotarou Yamaguchi, Yuta Kobayashi, Yota Takamura, Hiro Munekata, Teruo Ono, Takahiro Moriyama, Takuya Satoh

    AIP Advances   Vol. 14 ( 8 )   2024.8

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    Publishing type:Research paper (scientific journal)  

    We present the magneto-optical Kerr effect (MOKE) of (111)-oriented antiferromagnetic L12-Mn3Ir films epitaxially grown on MgO (111) substrates. We observed that the amplitude and sign of the polar MOKE change depending on the growth temperature. The Mn3Ir films grown at 800 and 600 °C have rotation angles of 41.6 and −4.6 mdeg and ellipticity angles of −15.3 and 9.1 mdeg, respectively. Residual strains owing to heteroepitaxial growth on the order of a few tenths of a percent can play a critical role in determining the amplitude and sign of the MOKE of a noncollinear antiferromagnet, unlike ferromagnets.

    DOI: 10.1063/5.0217261

    Web of Science

    Scopus

  5. Spin-torque ferromagnetic resonance based on current-induced impedance

    Yuta Kobayashi, Tomoya Itoh, Ryusuke Hisatomi, Takahiro Moriyama, Yoichi Shiota, Xin Fan, Teruo Ono

    Applied Physics Letters   Vol. 125 ( 2 )   2024.7

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    Publishing type:Research paper (scientific journal)  

    Spin-torque ferromagnetic resonance (ST-FMR) has been widely used for measuring damping-like spin-orbit torques in magnetic bilayers. Typically, the ratio between the damping-like and field-like spin-orbit torques are extrapolated based on the ferromagnetic resonance line shapes. However, when the field-like spin-orbit torque is unknown, the line shape analysis may lead to errors in extrapolating the damping-like spin-orbit torque. Here, we propose a modified version of the ST-FMR that allows extrapolation of both damping-like and field-like torques independently. By introducing an alternating current to the sample, the RF impedance is modulated, allowing detection via the reflected microwave. We show that the extrapolated field-like and damping-like torques in Py/Pt samples are consistent with the technique measuring current-induced linewidth and resonance field change but have much better signal-to-noise ratio. Our proposed method paves a way for more accurate measurement of spin-orbit torques.

    DOI: 10.1063/5.0222114

    Web of Science

    Scopus

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Books 1

  1. Magnetization dynamics in Antiferro- and ferri-magnets

    Takahiro Moriyama, Yoichi Shiota, Teruo Ono

    2022.6 

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    Language:Japanese

MISC 10

  1. Antiferromagnetic Materials for High-speed spintronics Invited

    Takahiro Moriyama

    THE JOURNAL OF THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS   Vol. 105 ( 12 ) page: 1400 - 1406   2022.12

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    Authorship:Lead author   Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

  2. Controlling Antiferromagnetic Order and THz Resonance Invited

    Takahiro Moriyama, Teruo Ono

    Magnetics Japan   Vol. 17 ( 5 ) page: 219 - 226   2022.10

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    Authorship:Lead author   Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

  3. Magnetization dynamics in Antiferro- and ferri-magnets Invited

    Takahiro Moriyama, Yoichi Shiota, Teruo Ono

      Vol. 77   page: 367 - 372   2022.6

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    Authorship:Lead author   Language:Japanese   Publishing type:Article, review, commentary, editorial, etc. (scientific journal)  

  4. Longitudinal conductance dependence of anomalous Hall effect in L1<sub>2</sub>-ordered antiferromagnetic Mn<sub>3</sub>Ir thin films

    小林裕太, 木俣基, 小野輝男, 森山貴広

    東北大学金属材料研究所強磁場超伝導材料研究センター年次報告   Vol. 2021   2022

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  5. Quantitative observation of optical activity induced by surface acoustic waves

    久富隆佑, 久富隆佑, 多賀光太郎, 大沼悠一, 佐々木遼, 佐々木遼, 宇佐見康二, 中村泰信, 中村泰信, 塩田陽一, 森山貴広, 小野輝男

    日本物理学会講演概要集(CD-ROM)   Vol. 76 ( 2 )   2021

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Presentations 148

  1. テラヘルツ反強磁性ダイナミクスの電気的検出 Invited

    森山貴広

    第63回電子スピンサイエンス学会年会  2024.11.3 

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    Event date: 2024.11

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  2. Electrical detection of antiferromagnetic dynamics Invited

    T. Moriyama

    The 9th International Workshop on Far-Infrared Technologies  2024.10.16 

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    Event date: 2024.10

    Language:English   Presentation type:Oral presentation (invited, special)  

  3. Electrical detection of antiferromagnetic dynamics Invited

    T. Moriyama

    ISAMMA2024  2024.8.4 

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    Event date: 2024.8

    Language:English   Presentation type:Oral presentation (invited, special)  

  4. 反強磁性薄膜のテラヘルツ分光 Invited

    森山貴広

    応用物理学会・日本磁気学会共同主催研究会 「エキゾチック磁性を活用したスピントロニクス研究の最前線」  2024.3.11  応用物理学会、日本磁気学会

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    Event date: 2024.3

    Language:Japanese  

    Venue:東京お茶の水  

  5. Electrical detection of antiferromagnetic dynamics in thin films by using gyrotron Invited

    Takahiro Moriyama

    Symposium on Frontier of Terahertz Science X  2023.12.21 

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    Event date: 2023.12

    Language:English   Presentation type:Oral presentation (invited, special)  

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KAKENHI (Grants-in-Aid for Scientific Research) 9

  1. Generation and detection of non-trivial spin current in synthetic altermagnets

    Grant number:23KK0093  2023.9 - 2027.3

    Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (International Collaborative Research)

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    Authorship:Principal investigator 

    Grant amount:\19760000 ( Direct Cost: \15200000 、 Indirect Cost:\4560000 )

  2. 反強磁性体テラヘルツスピントロニクスの創成

    Grant number:21H04562  2021.4 - 2024.3

    日本学術振興会  科学研究費助成事業  基盤研究(A)

    森山 貴広, 中村 浩次, 中村 浩次

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    Authorship:Principal investigator 

    Grant amount:\43160000 ( Direct Cost: \33200000 、 Indirect Cost:\9960000 )

    これまでスピントロニクスにおける主材料は専ら強磁性体であり、反強磁性体は様々な固定概念から応用・基礎研究がほとんど行われてこなかった材料・物理系であった。しかしながら、近年、申請者自身の主導するものを含む研究成果から、伝導電子スピンと反強磁性体の局在磁気モーメント(局在スピン)との相互作用が存在することが実験的に明らかになってきた。これらの成果を糸口として、「反強磁性体スピントロニクス」の研究が活発化している。本研究では、これらの研究成果をさらに発展させ、反強磁性体が持つ超高周波(THz帯域)の磁気共鳴周波数を積極的に利用した「反強磁性体テラヘルツスピントロニクス」の学理を構築し、スピントロニクスの動作原理を利用した次世代テラヘルツ基盤技術を創成することを目的とする。
    本年度は、α-Fe2O3の反強磁性共鳴について調査した。α-Fe2O3のFe3+カチオンをAl、Ru、Rh、Inなどで置換しことで反強磁性共鳴周波数を0.2~1THzの範囲で制御することに成功している。また、モーリン温度(α-Fe2O3の磁気異方性がゼロになる温度)と共鳴周波数の相関から、α-Fe2O3の磁気異方性の増減や共鳴周波数の変化についてミクロスコピックなメカニズムを考察し、解明した。これらの結果は、α-Fe2O3がポスト5Gなどの通信周波数>30GHzにおいて、フィルターや吸収材として利用可能な材料であることを示した重要な成果である。

  3. Exploration of ultra-high speed spintronic devices using antiferromagnets

    Grant number:19K21972  2019.6 - 2021.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Research (Exploratory)

    Takahiro Moriyama

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    Authorship:Principal investigator 

    Grant amount:\6500000 ( Direct Cost: \5000000 、 Indirect Cost:\1500000 )

    The purpose of this study is to understand the antiferromagnetic magnetization dynamics in the ultra-short time domain and to demonstrate the magnetization reversal device. First, we investigated the magnetization dynamics of antiferromagnetic materials such as NiO and α-Fe2O3, and found that the resonance frequency and damping constant, which are important for understanding the magnetization dynamics, can be controlled depending on the crystallinity and cation substitution elements. Second, we devised a photoconductive switch which generates and injects a picosecond current pulse into the antiferromagnetic element to reverse the magnetization. The magnetization reversal has not been clearly captured yet. Meanwhile, some issues have been identified regarding the optimization of the photoconductive switch and the current pulse introduction method. The research will be continued to achieve the goals.

  4. Spin dynamics in antiferromagnetic nanofilms studied by phonon-magnon interaction

    Grant number:18H01859  2018.4 - 2022.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nagakubo Akira

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    Authorship:Coinvestigator(s) 

    In this study, we studied the fundamental phono properties of NiO and the interaction between magnon and GHz-range longitudinal phonon to reveal and apply the phonon-magnon coupling in antiferromagnets. Our measurement for Pt/NiO/Pt nanofilms revealed that the elastic constant of NiO largely changes depending on deposition conditions and substrates. From ultrasound resonance spectroscopy measurement for a single bulk crystal, we also found that the antiferromagnetic order seriously affects the phonon properties, which change with deformation modes. These results will contribute to further study and application of the phonon properties of antiferromagnetic films.

  5. spin torque operation for antiferromagnetic spin devices

    Grant number:17H04924  2017.4 - 2020.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (A)

    Moriyama Takahiro

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    Authorship:Principal investigator 

    Grant amount:\24180000 ( Direct Cost: \18600000 、 Indirect Cost:\5580000 )

    Antiferromagnets have multiple magnetic sublattices and the magnetic moments on the sublattices are compensated by each other. Negligible net magnetization and small magnetic susceptibility of antiferromagnets were considered useless in spintronics. However, the present research found the possibility of the spin torque manipulation of the antiferromagnetic magnetic moment and the electrical reading of the direction of the magnetic moment. Based on the findings, non-volatile spin-torque operated antiferromagnetic memory devices were demonstrated. The achievement of this research strongly suggests that antiferromagnets can be novel and useful materials in spintronics.

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Industrial property rights 4

  1. 磁気メモリ素子及び該磁気メモリ素子に用いる磁性材料

    森山貴広, 小野輝男, 関 剛斎, 周 偉男, 高梨弘毅

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    Applicant:京都大学、東北大学

    Application no:特願2017-132264  Date applied:2017.7

  2. Seed Layer for Perpendicular Magnetic Anisotropy (PMA) Thin Film

    Takahiro Moriyama, Yu-Jen Wang, Ru-Ying Tong

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    Applicant:Headway Technologies, Inc.

    Application no:US 13/863545  Date applied:2013

    Announcement no:pending  Date announced:2014

    A magnetic thin film deposition having PMA (perpendicular magnetic anisotropy) is a multilayered fabrication of materials having differing crystal symmetries that smoothly transition by use of a seed layer that promotes symmetry matching. An interface between layers in the deposition, such as an interface between a layer of MgO and an Fe-containing ferromagnetic layer, is a source of perpendicular magnetic anisotropy which then propagates throughout the remainder of the deposition by means of the symmetry matching seed layer.

  3. Mg Discontinuous Insertion Layer for Improving MTJ Shunt

    Takahiro Moriyama, Yu-Jen Wang, Ru-Ying Tong

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    Applicant:Headway Technologies, Inc.

    Application no:US 13/739,016  Date applied:2013

    Announcement no:US20140197504 A1  Date announced:2014

    Patent/Registration no:8981505 

    A MTJ is disclosed with a discontinuous Mg or Mg alloy layer having a thickness from 1 to 3 Angstroms between a free layer and a capping layer in a bottom spin valve configuration. It is believed the discontinuous Mg layer serves to block conductive material in the capping layer from diffusing through the free layer and into the tunnel barrier layer thereby preventing the formation of conductive channels that function as electrical shunts within the insulation matrix of the tunnel barrier. As a result, the “low tail” percentage in a plot of magnetoresistive ratio vs Rp is minimized which means the number of high performance MTJ elements in a MTJ array is significantly increased, especially when a high temperature anneal is included in the MTJ fabrication process. The discontinuous layer is formed by a low power physical vapor deposition process.

  4. ELECTROMAGNETIC WAVE DETECTION METHODS AND APPARATUS

    Takahiro Moriyama, John Q Xiao

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    Applicant:University Of Delaware

    Application no:US 12/865,182  Date applied:2008

    Announcement no:US8669762 B2  Date announced:2014

    Patent/Registration no:8669762 

    Methods and apparatus for detecting an electromagnetic wave are provided. A device for use in an electromagnetic wave detector includes a first device layer having a first contact, a second device layer having a second contact, and a tunnel barrier layer and a resonating magnetic layer formed between the first and second device layers. The resonating magnetic layer produces a spin current responsive to an electromagnetic wave that extends into the first and second device layers. A charge differential present between the first and second contacts is dependent on the spin current.

 

Teaching Experience (Off-campus) 3

  1. Condensed matter physics

    2024.4 Nagoya University)

  2. Classical mechanics II

    2023.10 Nagoya University)

  3. Condensed matter physics (Graduate level)

    Kotyo University)

 

Social Contribution 1

  1. Vice-President and Treasurer, Cornell Japanese Graduate Students and Scholars Association

    Role(s):Planner, Organizing member

    2009.9 - 2010.9

Academic Activities 2

  1. MMM2023 Program Co-Chair

    Role(s):Planning, management, etc.

    IEEE and AIPP  2023.10 - 2023.11

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    Type:Competition, symposium, etc. 

  2. The 43rd annual conference in Magnetics in Japan

    Role(s):Planning, management, etc.

    Kyoto University  2019.9

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    Type:Academic society, research group, etc.