原著論文

  1. “Spontaneous Hall effect induced by collinear antiferromagnetic order at room temperature”
    R. Takagi, R. Hirakida, Y. Settai, R. Oiwa, H. Takagi, A. Kitaori, K. Yamauchi, H. Inoue, J. Yamaura, D. Nishio-Hamane, S. Itoh, S. Aji, H. Saito, T. Nakajima, T. Nomoto, R. Arita, S. Seki
    Nature Materials (in press)


  2. “Exotic spin excitations in a polar magnet VOSe2O5“
    T. Araki, R. Takagi, T. Kurumaji, Y. Tokura, M. Mochizuki, S. Seki
    Phys. Rev. Lett. 133, 136702 (2024).


  3. “Multistep topological transitions among meron and skyrmion crystals in a centrosymmetric magnet”
    H. Yoshimochi, R. Takagi, J. Ju, N. D. Khanh, H. Saito, H. Sagayama, H. Nakao, S. Itoh, Y. Tokura, T. Arima, S. Hayami, T. Nakajima, S. Seki
    Nature Physics 20, 1001 (2024).


  4. “SP-STM study of the multi-Q phases in GdRu2Si2”
    J. Spethmann, N. D. Khanh, H. Yoshimochi, R. Takagi, S. Hayami, Y. Motome, R. Wiesendanger, S. Seki, K. Bergmann
    Phys. Rev. Materials 8, 064404 (2024).


  5. “Task-adaptive physical reservoir computing”
    O. Lee, T. Wei, K. D Stenning, J. C. Gartside, D. Prestwood, S. Seki, A. Aqeel, K. Karube, N. Kanazawa, Y. Taguchi, C. Back, Y. Tokura, W. R. Branford, H. Kurebayashi
    Nature Materials 23, 79 (2024).


  6. “Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials”
    H. Takagi, R. Takagi, S. Minami, T. Nomoto, K. Ohishi, M.-T. Suzuki, Y. Yanagi, M. Hirayama, N. D. Khanh, K. Karube, H. Saito, D. Hashizume, R. Kiyanagi, Y. Tokura, R. Arita, T. Nakajima, S. Seki
    Nature Physics 19, 961 (2023).


  7. “Nonreciprocal Phonon Propagation in a Metallic Chiral Magnet”
    T. Nomura, X.-X. Zhang, R. Takagi, K. Karube, A. Kikkawa, Y. Taguchi, Y. Tokura, S. Zherlitsyn, Y. Kohama, S. Seki
    Phys. Rev. Lett. 130, 176301 (2023).


  8. “Quantum oscillations in the centrosymmetric skyrmion-hosting magnet GdRu2Si2“
    N. Matsuyama, T. Nomura, S. Imajo, T. Nomoto, R. Arita, K. Sudo, M. Kimata, N. D. Khanh, R. Takagi, Y. Tokura, S. Seki, K. Kindo, Y. Kohama
    Phys. Rev. B 107, 104421 (2023). [Editor's Suggestion]


  9. “Rhombic skyrmion lattice coupled with orthorhombic structural distortion in EuAl4“
    M. Gen, R. Takagi, Y. Watanabe, S. Kitou, H. Sagayama, N. Matsuyama, Y. Kohama, A. Ikeda, Y. Onuki, T. Kurumaji, T. Arima, S. Seki
    Phys. Rev. B 107, L020410 (2023).


  10. “Pattern recognition with neuromorphic computing using magnetic field-induced dynamics of skyrmions”
    T. Yokouchi, S. Sugimoto, B. Rana, S. Seki, N. Ogawa, Y. Shiomi, S Kasai, Y. Otani
    Science Advances 8, 5652 (2022).


  11. “Higher-order modulations in the skyrmion lattice phase of Cu2OSeO3“
    J. D. Reim, S. Matsuzaka, K. Makino, S. Aji, R. Murasaki, D. Higashi, D. Okuyama, Y. Nambu, E. P. Gilbert, N. Booth, S. Seki, Y. Tokura, T. J. Sato
    Phys. Rev. B 106, 104406 (2022).


  12. “Square and rhombic lattices of magnetic skyrmions in a centrosymmetric binary compound”
    R. Takagi, N. Matsuyama, V. Ukleev, L. Yu, J. S. White, S. Francoual, J. R. L. Mardegan, S. Hayami, H. Saito, K. Kaneko, K. Ohishi, Y. Onuki, T. Arima, Y. Tokura, T. Nakajima, S. Seki
    Nature Communications 13, 1472 (2022).


  13. “Direct visualization of the three-dimensional shape of skyrmion strings in a noncentrosymmetric magnet”
    S. Seki, M. Suzuki, M. Ishibashi, R. Takagi, N. D. Khanh, Y. Shiota, K. Shibata, W. Koshibae, Y. Tokura, T. Ono
    Nature Materials 21, 181 (2022).


  14. “Zoology of multiple-Q spin textures in a centrosymmetric tetragonal magnet with itinerant electrons”
    N. D. Khanh, T. Nakajima, S. Hayami, S. Gao, Y. Yamasaki, H. Sagayama, H. Nakao, R. Takagi, Y. Motome, Y. Tokura, T. Arima, S. Seki
    Advanced Science 2105452 (2022).


  15. “Enhanced gyrotropic birefringence and natural optical activity on electromagnon resonance in a helimagnet”
    S. Iguchi, R. Masuda, S. Seki, Y. Tokura, Y. Takahashi
    Nature Communications 12, 6674 (2021).


  16. “Tunable gigahertz dynamics of low-temperature skyrmion lattice in a chiral magnet”
    O. Lee, J. Sahliger, A. Aqeel, S. Khan, S. Seki, H. Kurebayashi, C. H. Back
    J. Phys.: Condens. Matter 34, 095801 (2021).


  17. “Hybridized magnon modes in the quenched skyrmion crystal”
    R. Takagi, M. Garst, J. Sahliger, C. H. Back, Y. Tokura, S. Seki
    Phys. Rev. B 104, 144410 (2021).


  18. “Coupling microwave photons to topological spin textures in Cu2OSeO3“
    S. Khan, O. Lee, T. Dion, C. W. Zollitsch, S. Seki, Y. Tokura, J. D. Breeze, and H. Kurebayashi
    Phys. Rev. B 104, L100402 (2021).


  19. “Real-space observations of 60-nm skyrmion dynamics in an insulating magnet under low heat flow”
    X. Z. Yu, F. Kagawa, S. Seki, M. Kubota, J. Masell, F. S. Yasin, K. Nakajima, M. Nakamura, M. Kawasaki, N. Nagaosa, Y. Tokura
    Nature Communications 12, 5079 (2021).


  20. “Topological defect-mediated skyrmion annihilation in three dimensions”
    M. T. Birch, D. Cortés-Ortuño, N. D. Khanh, S. Seki, A. Štefančič, G. Balakrishnan, Y. Tokura, P. D. Hatton
    Communications Physics 4, 175 (2021).


  21. “Nonreciprocity of spin waves in the conical helix state”
    N. Ogawa, L. Köhler, M. Garst, S. Toyoda, S. Seki, Y. Tokura
    PNAS 118, 2022927118 (2021).


  22. “Imaging the coupling between itinerant electrons and localised moments in the centrosymmetric skyrmion magnet GdRu2Si2“
    Y. Yasui, C. Butler, N. D. Khanh, S. Hayami, T. Nomoto, T. Hanaguri, Y. Motome, R. Arita, T. Arima, Y. Tokura, S. Seki
    Nature Communications 11, 5925 (2020).


  23. “Particle-size dependent structural transformation of skyrmion lattice”
    R. Takagi, Y. Yamasaki, T. Yokouchi, V. Ukleev, Y. Yokoyama, H. Nakao, T. Arima, Y. Tokura, S. Seki
    Nature Communications 11, 5685 (2020).


  24. “Structural analysis of high-pressure phase for skyrmion-hosting multiferroic Cu2OSeO3“
    E. Nishibori, S. Karatsu, C. Terakura, N. Takeshita, M. Kinoshita, S. Ishiwata, Y. Tokura, S. Seki
    Phys. Rev. B 102, 201106(R) (2020). (arXiv:2009.07577)


  25. “Bloch Lines Constituting Antiskyrmions Captured via Differential Phase Contrast”
    F. S. Yasin, L. Peng, R. Takagi, N. Kanazawa, S. Seki, Y. Tokura, X. Z. Yu
    Advanced Materials 32, 2004206 (2020).


  26. “Nanometric square skyrmion lattice in a centrosymmetric tetragonal magnet”
    N. D. Khanh, T. Nakajima, X. Z. Yu, S. Gao, K. Shibata, M. Hirschberger, Y. Yamasaki, H. Sagayama, H. Nakao, L. C. Peng, K. Nakajima, R. Takagi, T. Arima, Y. Tokura, S. Seki
    Nature Nanotechnology 15, 444 (2020). (arXiv:2003.00626)


  27. “Creation of magnetic skyrmions by surface acoustic waves”
    T. Yokouchi, S. Sugimoto, B. Rana, S. Seki, N. Ogawa, S. Kasai, Y. Otani
    Nature Nanotechnology 15, 361 (2020).


  28. “Controlled transformation of skyrmions and antiskyrmions in a non-centrosymmetric magnet”
    L. Peng, R. Takagi, W. Koshibae, K. Shibata, K. Nakajima, T. Arima, N. Nagaosa, S. Seki, X. Z. Yu, Y. Tokura
    Nature Nanotechnology 15, 181 (2020).


  29. “Propagation dynamics of spin excitations along skyrmion strings”
    S. Seki, M. Garst, J. Waizner, R. Takagi, N. D. Khanh, Y. Okamura, K. Kondou, F. Kagawa, Y. Otani, Y. Tokura
    Nature Communications 11, 256 (2020). (arXiv:1902.10302)


  30. “Emergent topological spin structures in the centrosymmetric cubic perovskite SrFeO3“
    S. Ishiwata, T. Nakajima, J. -H. Kim, D. S. Inosov, N. Kanazawa, J. S. White, J. L. Gavilano, R. Georgii, K. M. Seemann, G. Brandl, P. Manuel, D. D. Khalyavin, S. Seki, Y. Tokunaga, M. Kinoshita, Y. W. Long, Y. Kaneko, Y. Taguchi, T. Arima, B. Keimer, Y. Tokura
    Phys. Rev. B 101, 134406 (2020). [Editor's Suggestion] (arXiv:1806.02309)


  31. “Increased lifetime of metastable skyrmions by doping”
    M. T. Birch, R. Takagi, S. Seki, M. N. Wilson, F. Kagawa, A. Štefančič, G. Balakrishnan, R. Fan, P. Steadman, C. J. Ottley, M. Crisanti, R. Cubitt, T. Lancaster, Y. Tokura, P. D. Hatton
    Phys. Rev. B 100, 014425 (2019). [Editor's Suggestion] (arXiv:1809.02590)


  32. “Phonon Magnetochiral Effect”
    T. Nomura, X.-X. Zhang, S. Zherlitsyn, J. Wosnitza, Y. Tokura, N. Nagaosa, S. Seki
    Phys. Rev. Lett. 122, 145901 (2019). [Editor's Suggestion, Highlighted in Physics] (arXiv:1809.08775)


  33. “Magnon-photon coupling in a noncollinear magnetic insulator Cu2OSeO3“
    L. V. Abdurakhimov, S. Khan, N. A. Panjwani, J. D. Breeze, M. Mochizuki, S. Seki, Y. Tokura, J. J. L. Morton, and H. Kurebayashi
    Phys. Rev. B 99, 140401(R) (2019). [Editor's Suggestion] (arXiv:1802.07113)


  34. “Microwave Directional Dichroism Resonant with Spin Excitations in the Polar Ferromagnet GaV4S8“
    Y. Okamura, S. Seki, S. Bordacs, A. Butykai, V. Tsurkan, I. Kezsmarki, and Y. Tokura
    Phys. Rev. Lett. 122, 057202 (2019).


  35. “Multiple-q non-collinear magnetism in an itinerant hexagonal magnet”
    R. Takagi, J. S. White, S. Hayami, R. Arita, D. Honecker, H. M. Ronnow, Y. Tokura, S. Seki
    Science Advances 4, 3402 (2018).


  36. “Low-field bi-skyrmion formation in a noncentrosymmetric chimney ladder ferromagnet”
    R. Takagi, X. Z. Yu, J. S. White, K. Shibata, Y. Kaneko, G. Tatara, H. M. Ronnow, Y. Tokura, S. Seki
    Phys. Rev. Lett. 120, 037203 (2018).


  37. “Uniaxial-stress Effects on Helimagnetic Orders and Skyrmion Lattice in Cu2OSeO3“
    T. Nakajima, V. Ukleev, K. Ohishi, H. Oike, F. Kagawa, S. Seki, K. Kakurai, Y. Tokura, T. Arima
    J. Phys. Soc. Jpn. 87, 094709 (2018).


  38. “Stabilization of magnetic skyrmions by uniaxial tensile strain”
    S. Seki, Y. Okamura, K. Shibata, R. Takagi, N. D. Khanh, F. Kagawa, T. Arima, Y. Tokura
    Phys. Rev. B 96, 220404(R) (2017).


  39. “Emergence and magnetic-field variation of chiral-soliton lattice and skyrmion lattice in the strained helimagnet Cu2OSeO3“
    Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, and Y. Tokura
    Phys. Rev. B 96, 174417 (2017).


  40. “Nonlinear Ultrafast Spin Scattering in the Skyrmion Phase of Cu2OSeO3“
    M. C. Langner, S. Roy, S. W. Huang, J. D. Koralek, Y.-D. Chuang, G. L. Dakovski, J. J. Turner, J. S. Robinson, R. N. Coffee, M. P. Minitti, S. Seki, Y. Tokura, R. W. Schoenlein
    Phys. Rev. Lett. 119, 107204 (2017).


  41. “Spin-wave spectroscopy of the Dzyaloshinskii-Moriya interaction in room-temperature chiral magnets hosting skyrmions”
    R. Takagi, D. Morikawa, K. Karube, N. Kanazawa, K. Shibata, G. Tatara, Y. Tokunaga, T. Arima, Y. Taguchi, Y. Tokura, S. Seki
    Phys. Rev. B 95, 220406(R) (2017). (arXiv:1705.09001)


  42. “Directional electric-field induced transformation from skyrmion lattice to distinct helices in multiferroic Cu2OSeO3“
    Y. Okamura, Y. Yamasaki, D. Morikawa, T. Honda, V. Ukleev, H. Nakao, Y. Murakami, K. Shibata, F. Kagawa, S. Seki, T. Arima, Y. Tokura.
    Phys. Rev. B 95, 184411 (2017).


  43. “Thermal stability and irreversibility of skyrmion-lattice phases in Cu2OSeO3“
    K. Makino, J. D. Reim, D. Higashi, D. Okuyama, T. J. Sato, Y. Nambu, E. P. Gilbert, N. Booth, S. Seki, Y. Tokura
    Phys. Rev. B 95, 134412 (2017). (arXiv:1608.06359)


  44. “Transition to and from the skyrmion lattice phase by electric fields in a magnetoelectric compound”
    Y. Okamura, F. Kagawa, S. Seki, and Y. Tokura
    Nature Communications 7, 12669 (2016).


  45. “Magnetic reversal of electric polarization with fixed chirality of magnetic structure in a chiral-lattice helimagnet MnSb2O6“
    M. Kinoshita, S. Seki, T. J. Sato, Y. Nambu, T. Hong, M. Matsuda, H. Cao, S. Ishiwata, and Y. Tokura
    Phys. Rev. Lett. 117, 047201 (2016).


  46. “Magnetochiral nonreciprocity of volume spin wave propagation in chiral-lattice ferromagnets”
    S. Seki, Y. Okamura, K. Kondou, K. Shibata, M. Kubota, R. Takagi, F. Kagawa, M. Kawasaki, G. Tatara, Y. Otani, and Y. Tokura
    Phys. Rev. B 93, 235131 (2016). (arXiv:1505.02868)


  47. “Thermal generation of spin current in a multiferroic helimagnet”
    R. Takagi, Y. Tokunaga, T. Ideue, Y. Taguchi, Y. Tokura and S. Seki
    APL Mater. 4, 032502 (2016). [invited] (arXiv:1602.04011)


  48. “Thermal generation of spin current in an antiferromagnet”
    S. Seki, T. Ideue, M. Kubota, Y. Kozuka, R. Takagi, M. Nakamura, Y. Kaneko, M. Kawasaki, and Y. Tokura
    Phys. Rev. Lett. 115, 266601 (2015). [Editor's Suggestion, Highlighted in Nature Nanotechnology and Physics] (arXiv:1508.02555)


  49. “Microwave Magnetochiral Dichroism in the Chiral-Lattice Magnet Cu2OSeO3“
    Y. Okamura, F. Kagawa, S. Seki, M. Kubota, M. Kawasaki, and Y. Tokura
    Phys. Rev. Lett. 114, 197202 (2015).


  50. “Ultrafast optical excitation of magnetic skyrmions”
    N. Ogawa, S. Seki and Y. Tokura
    Scientific Reports 5, 9552 (2015).


  51. “Magnetochiral dichroism resonant with electromagnons in a helimagnet”
    S. Kibayashi, Y. Takahashi, S. Seki, and Y. Tokura
    Nature Communications 5, 4583 (2014).


  52. “Coupled skyrmion sublattices in Cu2OSeO3“
    M.C. Langner, S. Roy, S. K. Mishra, J. C. T. Lee, X. W. Shi, M. A. Hossain, Y.-D. Chuang, S. Seki, Y. Tokura, S. D. Kevan, and R. W. Schoenlein
    Phys. Rev. Lett. 112, 167202 (2014). (arXiv:1402.2947)


  53. “Thermally driven ratchet motion of a skyrmion microcrystal and topological magnon Hall effect”
    M. Mochizuki, X. Z. Yu, S. Seki, N. Kanazawa, W. Koshibae, J. Zang, M. Mostovoy, Y. Tokura, and N. Nagaosa
    Nature Materials 13, 241 (2014).


  54. “Microwave magnetoelectric effect via skyrmion resonant modes in a helimagnetic multiferroics”
    Y. Okamura, F. Kagawa, M. Mochizuki, M. Kubota, S. Seki, S. Ishiwata, M. Kawasaki, Y. Onose, and Y. Tokura
    Nature Communications 4, 2391 (2013).


  55. “Optimal Tc for electron-doped cuprate realized under high pressure”
    S. Ishiwata, D. Kotajima, N. Takeshita, C. Terakura, S. Seki, and Y. Tokura
    J. Phys. Soc. Jpn. 82, 063705 (2013).


  56. “Superconductivity in CuxIrTe2 driven by interlayer hybridization”
    M. Kamitani, M. S. Bahramy, R. Arita, S. Seki, T. Arima, Y. Tokura, and S. Ishiwata
    Phys. Rev. B 87, 180501 (2013).


  57. “Magnetoelectric resonances and predicted microwave diode effect of the skyrmion crystal in a multiferroic chiral-lattice magnet”
    M. Mochizuki and S. Seki
    Phys. Rev. B 87, 134403 (2013). (arXiv:1303.4491v1)


  58. “Magnetoelectric responses induced by domain rearrangement and spin structural change in triangular-lattice helimagnets NiI2 and CoI2“
    T. Kurumaji, S. Seki, S. Ishiwata, H. Murakawa, Y. Kaneko, and Y. Tokura
    Phys. Rev. B 87, 014429 (2013).


  59. “Magnetoelectric nature of skyrmions in a chiral magnetic insulator Cu2OSeO3“
    S. Seki, S. Ishiwata, and Y. Tokura
    Phys. Rev. B 86, 060403(R) (2012). (arXiv:1206.4404v1)


  60. “Observation of magnetic excitations of skyrmion crystal in a helimagnetic insulator Cu2OSeO3“
    Y. Onose, Y. Okamura, S. Seki, S. Ishiwata, and Y. Tokura
    Phys. Rev. Lett. 109, 037603 (2012). (arXiv:1204.5009v1)


  61. “Formation and rotation of skyrmion crystal in the chiral-lattice insulator Cu2OSeO3“
    S. Seki, J.-H. Kim, D. S. Inosov, R. Georgii, B. Keimer, S. Ishiwata, and Y. Tokura
    Phys. Rev. B 85, 220406(R) (2012). (arXiv:1206.5220v1)


  62. “Observation of Skyrmions in a Multiferroic Material”
    S. Seki, X. Z. Yu, S. Ishiwata, and Y. Tokura
    Science 336, 198 (2012).


  63. “Magnetic-field induced competition of two multiferroic orders in a triangular-lattice helimagnet MnI2“
    T. Kurumaji, S. Seki, S. Ishiwata, H. Murakawa, Y. Tokunaga, Y. Kaneko, and Y. Tokura
    Phys. Rev. Lett. 106, 167206 (2011). (arXiv:1103.5294v1)


  64. “Effect of Spin Dilution on the Magnetic State of Delafossite CuCrO2 with an S = 3/2 Antiferromagnetic Triangular Sublattice”
    T. Okuda, K. Uto, S. Seki, Y. Onose, Y. Tokura, R. Kajimoto, and M. Matsuda
    J. Phys. Soc. Jpn. 80, 014711 (2011).


  65. “Electromagnons in the spin collinear state of a triangular lattice antiferromagnet”
    S. Seki, N. Kida, S. Kumakura, R. Shimano, and Y. Tokura
    Phys. Rev. Lett. 105, 097207 (2010). (arXiv:1008.4709v1)


  66. “Cupric chloride CuCl2 as an S = 1/2 chain multiferroic”
    S. Seki, T. Kurumaji, S. Ishiwata, H. Matsui, H. Murakawa, Y. Tokunaga, Y. Kaneko, T. Hasegawa, and Y. Tokura
    Phys. Rev. B 82, 064424 (2010). (arXiv:1008.5226v1)


  67. “Electronic structure, magnetic, and dielectric properties of the edge-sharing copper oxide chain compound NaCu2O2“
    Ph. Leininger, M. Rahlenbeck, M. Raichle, B. Bohnenbuck, A. Maljuk, C. T. Lin, B. Keimer, E. Weschke, E. Schierle, S. Seki, Y. Tokura, and J. W. Freeland
    Phys. Rev. B 81, 085111 (2010). (arXiv:0912.0168v1)


  68. “Magnetic digital flop of ferroelectric domain with fixed spin chirality in a triangular lattice helimagnet”
    S. Seki, H. Murakawa, Y.Onose, and Y. Tokura
    Phys. Rev. Lett. 103, 237601 (2009). (arXiv:0906.0324v2)


  69. Effect of Quenched Disorder on Charge Ordering Structure in RE1.67AE0.33NiO4 (RE = La, Pr, Nd, Sm; AE = Ca, Sr)
    X. Yu, T. Arima, S. Seki, T. Asaka, K. Kimoto, Y. Tokura, and Y. Matsui
    J. Phys. Soc. Jpn. 77, 093709 (2008).


  70. “Spin-driven ferroelectricity in triangular lattice antiferromagnets ACrO2 (A = Cu, Ag, Li, or Na) “
    S. Seki, Y.Onose, and Y. Tokura
    Phys. Rev. Lett. 101, 067204 (2008). (arXiv:0801.3757v1)


  71. “Correlation between spin helicity and electric polarization vector in quantum-spin chain magnet LiCu2O2“
    S. Seki, Y. Yamasaki, M. Soda, M. Matsuura, K. Hirota, Y. Tokura
    Phys. Rev. Lett. 100, 127201 (2008). (arXiv:0801.2533v1)


  72. “Impurity-doping-induced ferroelectricity in the frustrated antiferromagnet CuFeO2“
    S. Seki, Y. Yamasaki, Y. Shiomi, S.Iguchi, Y.Onose, and Y. Tokura
    Phys. Rev. B 75, 100403(R) (2007). (arXiv:cond-mat/0611255v1)