Publication

Review Article

  1. 速水 賢,八城 愛美,柳 有起,楠瀬 博明,
    "ミクロな多極子による電子物性の表現論 (その1)"
    固体物理 54, 131 (2019)

  2. C. D. Batista, S.-Z. Lin, S. Hayami, and Y. Kamiya,
    "Frustration and chiral orderings in correlated electron systems"
    Rep. Prog. Phys. 79, 084504 (2016)

  3. 速水 賢,楠瀬 博明,求 幸年,
    "遍歴電子系における自発的な空間反転対称性の破れ -非従来型多極子秩序とスピン・バレー分裂,非対角応答-"
    固体物理 50, 217 (2015)

Preprint

  1. Y. Su, S. Hayami, and S.-Z. Lin
    "Anomalous charge transport in magnetic insulators with multiple-Q spin textures"
    Preprint (arXiv:1904.05473, Condensed Matter)

  2. M. Naka, S. Hayami, H. Kusunose, Y. Yanagi, Y. Motome, and H. Seo,
    "Spin current generation in organic antiferromagnets"
    Preprint (arXiv:1902.02506, Condensed Matter)

Paper

  1. S. Hayami, H. Kusunose, and Y. Motome,
    "Magnetic Vortex Induced by Nonmagnetic Impurity in Ferromagnets: Magnetic Multipole and Toroidal around the Vacancy"
    J. Phys. Soc. Jpn. 88, 063702 (2019)
    Preprint (arXiv:1905.07669, Condensed Matter)

  2. M.-T. Suzuki, T. Nomoto, R. Arita, Y. Yanagi, S. Hayami, and H. Kusunose,
    "Multipole expansion for magnetic structures: A generation scheme for symmetry-adapted orthonormal basis set in crystallographic point group"
    Phys. Rev. B 99, 174407 (2019) [selected in Editors' Suggestion]
    Preprint (arXiv:1902.10819, Condensed Matter)

  3. M. Yatsushiro and S. Hayami,
    "Atomic-Scale Magnetic Toroidal Dipole under Odd-Parity Hybridization"
    J. Phys. Soc. Jpn. 88, 054708 (2019)
    Preprint (arXiv:1903.04708, Condensed Matter)

  4. S. Hayami, Y. Yanagi, H. Kusunose, and Y. Motome,
    "Electric Toroidal Quadrupoles in Spin-Orbit-Coupled Metal Cd2Re2O7"
    Phys. Rev. Lett. 122, 147602 (2019) [selected as Cover image and PDF FILE]
    Preprint (arXiv:1812.01249, Condensed Matter)

  5. S. Hayami and Y. Motome,
    "Effect of magnetic anisotropy on Skyrmions with a high topological number in itinerant magnets"
    Phys. Rev. B 99, 094420 (2019)
    Preprint (arXiv:1811.11336, Condensed Matter)

  6. R. Takagi, J. S. White, S. Hayami, R. Arita, D. Honecker, H. M. Rønnow, Y. Tokura, and S. Seki,
    "Multiple-q noncollinear magnetism in an itinerant hexagonal magnet"
    Sci. Adv. 4, eaau3402 (2018)

  7. S. Hayami, M. Yatsushiro, Y. Yanagi, and H. Kusunose,
    "Classification of atomic-scale multipoles under crystallographic point groups and application to linear response tensors"
    Phys. Rev. B 98, 165110 (2018) [selected in Editors' Suggestion]
    Preprint (arXiv:1806.01964, Condensed Matter)

  8. S. Hayami and Y. Motome,
    "Néel- and Bloch-Type Magnetic Vortices in Rashba Metals"
    Phys. Rev. Lett. 121, 137202 (2018) [selected as Cover image and PDF FILE]
    Preprint (arXiv:1803.01543, Condensed Matter)

  9. S. Hayami and H. Kusunose,
    "Microscopic Description of Electric and Magnetic Toroidal Multipoles in Hybrid Orbitals"
    J. Phys. Soc. Jpn. 87, 033709 (2018)
    Preprint (arXiv:1712.02927, Condensed Matter)

  10. S. Hayami, H. Kusunose, and Y. Motome,
    "Emergent odd-parity multipoles and magnetoelectric effects on a diamond structure: implication to 5d transition metal oxides AOsO4 (A= K, Rb, and Cs)"
    Phys. Rev. B 97, 024414 (2018)
    Preprint (arXiv:1711.09507, Condensed Matter)

  11. Y. Yanagi, S. Hayami, and H. Kusunose,
    "Manipulating magnetoelectric effect -- Essence learned from Co4Nb2O9"
    Phys. Rev. B 97, 020404 (2018)
    Preprint (arXiv:1712.03918, Condensed Matter)

  12. R. Ozawa, S. Hayami, K. Barros, and Y. Motome,
    "Shape of magnetic domain walls formed by coupling to mobile charges"
    Phys. Rev. B 96, 094417 (2017)
    Preprint (arXiv:1609.07189, Condensed Matter)

  13. S. Hayami, R. Ozawa, and Y. Motome,
    "Effective bilinear-biquadratic model for noncoplanar ordering in itinerant magnets"
    Phys. Rev. B 95, 224424 (2017), erratum [selected in Kaleidoscopes]
    Preprint (arXiv:1703.07690, Condensed Matter)

  14. R. Ozawa, S. Hayami, and Y. Motome,
    "Zero-Field Skyrmions with a High Topological Number in Itinerant Magnets"
    Phys. Rev. Lett. 118, 147205 (2017)
    Preprint (arXiv:1703.03227, Condensed Matter)

  15. S. Hayami, S.-Z. Lin, Y. Kamiya, and C. D. Batista
    "Vortices, skyrmions, and chirality waves in frustrated Mott insulators with a quenched periodic array of impurities"
    Phys. Rev. B 94, 174420 (2016)
    Preprint (arXiv:1607.07100, Condensed Matter)

  16. R. Ozawa, S. Hayami, K. Barros, G. W. Chern, Y. Motome, and C. D. Batista,
    "Vortex Crystals with Chiral Stripes in Itinerant Magnets"
    J. Phys. Soc. Jpn. 85, 103703 (2016)
    Preprint (arXiv:1510.06830, Condensed Matter)

  17. S. Hayami, H. Kusunose, and Y. Motome,
    "Emergent spin-valley-orbital physics by spontaneous parity breaking"
    J. Phys.: Condens. Matter 28, 395601 (2016)
    Preprint (arXiv:1607.05782, Condensed Matter)

  18. S. Hayami, R. Ozawa, and Y. Motome,
    "Engineering chiral density waves and topological band structures by multiple-Q superpositions of collinear up-up-down-down orders"
    Phys. Rev. B 94, 024424 (2016)
    Preprint (arXiv:1603.06646, Condensed Matter)

  19. S. Hayami, S.-Z. Lin, and C. D. Batista,
    "Bubble and skyrmion crystals in frustrated magnets with easy-axis anisotropy"
    Phys. Rev. B 93, 184413 (2016)
    Preprint (arXiv:1601.02064, Condensed Matter)

  20. S.-Z. Lin, S. Hayami, and C. D. Batista
    "Magnetic Vortex Induced by Nonmagnetic Impurity in Frustrated Magnets"
    Phys. Rev. Lett. 116, 187202 (2016)

  21. S. Hayami, H. Kusunose, and Y. Motome,
    "Asymmetric Magnon Excitation by Spontaneous Toroidal Ordering"
    J. Phys. Soc. Jpn. 85, 053705 (2016)
    Preprint (arXiv:1508.05627, Condensed Matter)

  22. S.-Z. Lin and S. Hayami,
    "Ginzburg-Landau theory for skyrmions in inversion-symmetric magnets with competing interactions"
    Phys. Rev. B 93, 064430 (2016)
    Preprint (arXiv:1512.05012, Condensed Matter)

  23. S. Hayami, H. Kusunose, and Y. Motome,
    "Spontaneous multipole ordering by local parity mixing"
    J. Phys. Soc. Jpn. 84, 064717 (2015)
    Preprint (arXiv:1502.00057, Condensed Matter)

  24. S. Hayami and Y. Motome,
    "Topological semimetal-to-insulator phase transition between noncollinear and noncoplanar multiple-Q states on a square-to-triangular lattice"
    Phys. Rev. B 91, 075104 (2015)
    Preprint (arXiv:1412.0752, Condensed Matter)

  25. S. Hayami, H. Kusunose, and Y. Motome,
    "Spontaneous parity breaking in spin-orbital coupled systems"
    Phys. Rev. B 90, 081115(R) (2014)
    Preprint (arXiv:1406.2093, Condensed Matter)

  26. S. Hayami and Y. Motome,
    "Multiple-Q instability by (d-2)-dimensional connections of Fermi surfaces"
    Phys. Rev. B 90, 060402(R) (2014)
    Preprint (arXiv:1406.3119, Condensed Matter)

  27. S. Hayami, H. Kusunose, and Y. Motome,
    "Toroidal order in metals without local inversion symmetry"
    Phys. Rev. B 90, 024432 (2014) [selected in Editors' Suggestion]
    Preprint (arXiv:1404.1156, Condensed Matter)

  28. S. Hayami, T. Misawa, Y. Yamaji, and Y. Motome,
    "Three-dimensional Dirac electrons on a cubic lattice with noncoplanar multiple-Q order"
    Phys. Rev. B 89, 085124 (2014)
    Preprint (arXiv:1305.5031, Condensed Matter)

  29. S. Hayami, M. Udagawa, and Y. Motome,
    "Partial Disorder and Metal-Insulator Transition in the Periodic Anderson Model on a Triangular Lattice"
    J. Phys. Soc. Jpn. 81,103707 (2012)
    Preprint (arXiv:1208.4691, Condensed Matter)

  30. S. Hayami, M. Udagawa, and Y. Motome,
    "Partial Disorder in the Periodic Anderson Model on a Triangular Lattice"
    J. Phys. Soc. Jpn. 80, 073704 (2011)
    Preprint(arxiv:1105.3271, Condensed Matter)

Proceedings

  1. S. Hayami and Y. Motome,
    "Multiple-Q Magnetic States in Spin-Orbit Coupled Metals"
    IEEE Transactions on Magnetics 55, 1500107 (2018)

  2. Y. Yanagi, S. Hayami, and H. Kusunose,
    "Theory of magnetoelectric response in Co4Nb2O9"
    Physica B: Condensed Matter 536, 107-110 (2018)

  3. S. Hayami, H. Kusunose, and Y. Motome,
    "Mean-field study of correlation-induced antisymmetric spin-orbit coupling in a two-orbital honeycomb model"
    Physica B: Condensed Matter 536, 649-653 (2018)

  4. Y. Sugita, S. Hayami, and Y. Motome,
    "Antisymmetric Spin-Orbit Coupling in a d-p Model on a Zigzag Chain"
    Physics Procedia 75, 419-425 (2015)

  5. S. Hayami, H. Kusunose, and Y. Motome,
    "Toroidal order in a partially disordered state on a layered triangular lattice: implication to UNi4B"
    J. Phys.: Conf. Ser. 592, 012101 (2015)
    Preprint (arXiv:1409.3657, Condensed Matter)

  6. S. Hayami, H. Kusunose, and Y. Motome,
    "Quantum spin Hall effect in a two-orbital model on a honeycomb lattice"
    J. Phys.: Conf. Ser. 592, 012131 (2015)
    Preprint (arXiv:1409.2142, Condensed Matter)

  7. S. Hayami, T. Misawa, and Y. Motome,
    "Charge Order with a Noncoplanar Triple-Q Magnetic Order on a Cubic Lattice"
    JPS Conf. Proc. 3, 016016 (2014)
    Preprint (arXiv:1310.1982, Condensed Matter)

  8. S. Hayami, M. Udagawa, and Y. Motome,
    "Carrier doping to a partially disordered state in the periodic Anderson model on a triangular lattice"
    J. Phys.: Conf. Ser. 400, 032018 (2012)
    Preprint (arXiv:1107.4401, Condensed Matter)

Press Release

  1. 北海道大学理化学研究所 プレスリリース
    "磁気渦の新しい生成機構を発見 -磁気渦を情報担体とする磁気記憶素子の実現に期待-"
  2. マイナビニュース (2018/11/25)
    "理研と北大、磁気渦の新しい生成機構を発見"
  3. 北海道大学東京大学大学院工学系研究科 プレスリリース
    "高いトポロジカル数を持つ磁気スキルミオンを発見 -磁場によるトポロジーの多段スイッチングが可能に-"
  4. 日本経済新聞 (2017/04/03)
    "東大、高いトポロジカル数をもつ磁気スキルミオンを発見"
  5. 日経テクノロジーonline (2017/04/04)
    "多段スイッチングを可能とする磁気スキルミオン"
  6. 日刊工業新聞 (2017/04/04)
    "東大、トポロジカル数持つ渦状スピン磁性体を発見"