Emergent magnetic monopoles and their dynamics in solids

• Project/Area Number: 15H05456
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: Kanazawa Naoya 東京大学, 大学院工学系研究科(工学部), 助教 (10734593)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥20,930,000 (Direct Cost: ¥16,100,000、Indirect Cost: ¥4,830,000); Fiscal Year 2016: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2015: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000)
• Keywords: トポロジー / 強相関電子系 / 物性実験 / キラル磁性体 / モノポール / スピントロニクス / スピンエレクトロニクス

Outline of Final Research Achievements

Elementary particles with electric charges, such as protons and electrons, are fundamental particles, forming our world. In contrast, magnetic monopoles with magnetic charges, i.e., particles as sources or sinks of magnetic field, have not been identified so far. The classical electromagnetism is therefore structured under assumption of their non-existence. However, it is theoretically proposed that we can create fictitious magnetic monopoles in materials by utilizing the geometric phase of electrons. In this research project, we have focused on topology of spin textures and realized emergence of magnetic monopoles and novel electromagnetic effects associated with their pair-annihilation dynamics.

Research Products

• [Int'l Joint Research] Paul Scherrer Institut/Ecole polytechnique federale de Lausanne(Switzerland)
• [Int'l Joint Research] Institut Laue-Langevin(France)
• [Int'l Joint Research] Paul Scherrer Institut/Ecole polytechnique federale de Lausanne(Switzerland)
• [Int'l Joint Research] Institut Laue-Langevin(France)
• [Journal Article] Noncentrosymmetric Magnets Hosting Magnetic Skyrmions (2017)
  • Author(s): Naoya Kanazawa, Shinichiro Seki, Yoshinori Tokura
  • Journal Title: Advanced Materials Volume: Online Issue: 25 Pages: 1603227-1603227
  • DOI: 10.1002/adma.201603227
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Temperature and Magnetic Field Dependence of the Internal and Lattice Structures of Skyrmions by Off-Axis Electron Holography (2017)
  • Author(s): K. Shibata, A. Kovacs, N.S. Kiselev, N. Kanazawa, R.E. Dunin-Borkowski, and Y. Tokura
  • Journal Title: Physical Review Letters Volume: 118 Issue: 8
  • DOI: 10.1103/physrevlett.118.087202
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Direct observation of anisotropic magnetic field response of the spin helix in FeGe thin films (2016)
  • Author(s): N. Kanazawa, J. S. White, H. M. Ronnow, C. D. Dewhurst, Y. Fujishiro, A. Tsukazaki, Y. Kozuka, M. Kawasaki, M. Ichikawa, F. Kagawa, and Y. Tokura
  • Journal Title: Physical Review B Volume: 94 Issue: 18
  • DOI: 10.1103/physrevb.94.184432
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe (2016)
  • Author(s): A. Dussaux, P. Schoenherr, K. Koumpouras, J. Chico, K. Chang, L. Lorenzelli, N. Kanazawa, Y. Tokura, M. Garst, A. Bergman, C. L. Degen, and D. Meier
  • Journal Title: Nature Communications Volume: 7 Issue: 1
  • DOI: 10.1038/ncomms12430
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Critical phenomena of emergent magnetic monopoles in a chiral magnet (2016)
  • Author(s): N. Kanazawa, Y. Nii, X. -X. Zhang, A. S. Mishchenko, G. De Filippis, F. Kagawa, Y. Iwasa, N. Nagaosa, and Y. Tokura
  • Journal Title: Nature Communications Volume: 7 Issue: 1 Pages: 11622-11622
  • DOI: 10.1038/ncomms11622
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Variation of spin-orbit coupling and related properties in skyrmionic system Mn1-xFexGe (2016)
  • Author(s): N. Kanazawa, K. Shibata, and Y. Tokura
  • Journal Title: New Journal of Physics Volume: 18 Issue: 4 Pages: 045006-045006
  • DOI: 10.1088/1367-2630/18/4/045006
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice (2015)
  • Author(s): H. Oike, A. Kikkawa, N. Kanazawa, Y. Taguchi, M. Kawasaki, Y. Tokura, F. Kagawa
  • Journal Title: Nature Physics Volume: 12 Issue: 1 Pages: 62-62
  • DOI: 10.1038/nphys3506
  • Peer Reviewed
• [Journal Article] Dynamical process of skyrmion-helical magnetic transformation of the chiral-lattice magnet FeGe probed by small-angle resonant soft x-ray scattering (2015)
  • Author(s): Y. Yamasaki, D. Morikawa, T. Honda, H. Nakao, Y. Murakami, N. Kanazawa, M. Kawasaki, T. Arima, and Y. Tokura
  • Journal Title: Physical Review B Volume: 92 Issue: 22 Pages: 224201-224201
  • DOI: 10.1103/physrevb.92.220421
  • Peer Reviewed / Open Access
• [Journal Article] Formation of In-plane Skyrmions in Epitaxial MnSi Thin Films as Revealed by Planar Hall Effect (2015)
  • Author(s): T. Yokouchi, N. Kanazawa, A. Tsukazaki, Y. Kozuka, A. Kikkawa, Y. Taguchi, M. Kawasaki, M. Ichikawa, F. Kagawa, Y. Tokura
  • Journal Title: Journal of the Physical Society of Japan Volume: 84 Issue: 10 Pages: 104708-104708
  • DOI: 10.7566/jpsj.84.104708
  • NAID: 210000133706
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Real-Space Observation of Short-Period Cubic Lattice of Skyrmions in MnGe (2015)
  • Author(s): Toshiaki Tanigaki, Kiyou Shibata, Naoya Kanazawa, Xiuzhen Yu, Yoshinori Onose, Hyun Soon Park, Daisuke Shindo, Yoshinori Tokura
  • Journal Title: Nano Letters Volume: 15(8) Issue: 8 Pages: 5438-5442
  • DOI: 10.1021/acs.nanolett.5b02653
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Large anisotropic deformation of skyrmions in strained crystal (2015)
  • Author(s): K. Shibata, J. Iwasaki, N. Kanazawa, S. Aizawa, T. Tanigaki, M. Shirai, T. Nakajima, M. Kubota, M. Kawasaki, H. S. Park, D.Shindo, N. Nagaosa, Y. Tokura
  • Journal Title: Nature Nanotechnology Volume: 10 Issue: 7 Pages: 589-589
  • DOI: 10.1038/nnano.2015.113
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] MnGe薄膜におけるトポロジカルスピン構造への磁気異方性の効果 (2017)
  • Author(s): 金澤直也, Jonathan White, Henrik Ronnow, Charles Dewhurst, 塚﨑敦, 小塚裕介, 川﨑雅司, 市川昌和, 賀川史敬, 十倉好紀
  • Organizer: 日本物理学会第72回年次大会
  • Place of Presentation: 大阪大学豊中キャンパス(大阪府・豊中市)
  • Year and Date: 2017-03-17
• [Presentation] Control of chiral magnetic states in B20-type compounds by tuning magnetic anisotropy (2017)
  • Author(s): Naoya Kanazawa
  • Organizer: The 37th REIMEI Workshop on Frontiers of Correlated Quantum Matters and Spintronics
  • Place of Presentation: iVil(茨城県・東海村)
  • Year and Date: 2017-01-13
  • Int'l Joint Research / Invited
• [Presentation] FeGe薄膜中のらせん磁気構造に対する磁気異方性の効果 (2016)
  • Author(s): 金澤直也, Jonathan White, Henrik Ronnow, Charles Dewhurst, 藤代有絵子, 塚﨑敦, 小塚裕介, 川﨑雅司, 市川昌和, 賀川史敬, 十倉好紀
  • Organizer: 日本物理学会 第68回年次大会
  • Place of Presentation: 宮城県、仙台市、東北学院大学
  • Year and Date: 2016-03-19
• [Presentation] キラルな磁性体におけるスキルミオンの発現と創発物性 (2015)
  • Author(s): 金澤直也
  • Organizer: 第2回 大学院リーディングセミナー ～物質科学最前線と未来創造～
  • Place of Presentation: 東京都、文京区、東京大学
  • Year and Date: 2015-12-07
  • Invited
• [Presentation] Skyrmion Formation in B20-type Germanides (2015)
  • Author(s): Naoya Kanazawa
  • Organizer: Workshop on "Topological Magnets"
  • Place of Presentation: 埼玉県、和光市、理化学研究所
  • Year and Date: 2015-05-25
  • Int'l Joint Research
• [Presentation] Skyrmions in bulks and films of B20-type compounds (2015)
  • Author(s): Naoya Kanazawa
  • Organizer: Hefei mini-workshop on skyrmions
  • Place of Presentation: 中国、合肥、High Magnetic Field Laboratory of CAS
  • Year and Date: 2015-05-18
  • Int'l Joint Research / Invited
• [Remarks] 東京大学十倉研究室ホームページ中の個人ページ
  • URL: http://www.cmr.t.u-tokyo.ac.jp/members/kanazawa.shtml