研究業績

[論文]

  1. "Extrinsic origin of nonreciprocal resistance in a non-chiral organic superconductor"
    Haruki Fuse, Yoshitaka Kawasugi, Hiroshi M. Yamamoto, Reizo Kato, Naoya Tajima, Appl. Phys. Lett., 128, 241906 (2026).

  2. "Anomalous Phase-Coherence Scaling in a Quantum-Critical Dirac Semimetal"
    Sana Nakamichi, Ryotaro Kobara, Yoshinari Unozawa, Yoshitaka Kawasugi, Sakura Hiramoto, Koki Funatsu, Toshio Naito, Masafumi Tamura, Reizo Kato, Yutaka Nishio, and Naoya Tajima, J. Phys. Soc. Jpn., 95, 063703 (2026).

  3. "Magnetotransport of the square-net topological semimetal with magnetization plateaus DyAgSb2"
    S. Kusakabe, R. Mikawa, H. Takei, T. Katsufuji, Y. Kawasugi, and T. Suzuki, Phys. Rev. B, 112, 205119 (2025).

  4. "Off-diagonal thermoelectric effect and its gate tuning in molecular conductor κ-(BEDT-TTF)2Cu[N(CN)2]Cl"
    Yuki Daigo, Yoshitaka Kawasugi, Hiroshi M. Yamamoto, Reizo Kato, and Naoya Tajima, Appl. Phys. Lett., 126, 261901 (2025).

  5. "Molecular Conductors Based on Dimethylcyclohexene-Fused Tetrathiafulvalene"
    by Masahiro Fujisaki,Ryoya Naito,Takashi Shirahata, Yoshitaka Kawasugi,Naoya Tajima, and Yohji Misaki, Chemistry, 6, 1509-1522 (2024).

  6. "Evidence for Three-dimensional Dirac Semimetal State in Strongly Correlated Organic Quasi-two-dimensional Material"
    Naoya Tajima, Yoshitaka Kawasugi, Takao Morinari, Ryuhei Oka, Toshio Naito, and Reizo Kato, J. Phys. Soc. Jpn., 92, (2023) 123702/1-4.


  7. "Negative Magnetoresistance near the Mott Metal-Insulator Transition in the Quantum Spin Liquid Candidate κ-(BEDT-TTF)2Cu2(CN)3"
    Yoshitaka Kawasugi, Shutaro Yamazaki, Andrej Pustogow, and Naoya Tajima, J. Phys. Soc. Jpn., 92, (2023) 065001/1-2.


  8. "Observations of ν = 1 Quantum Hall Effect and Inter-Band Effects of Magnetic Fields on Hall Conductivity in Organic Massless Dirac Fermion System α-(BETS)2I3 under Pressure"
    Kazuyuki Iwata, Akito Koshiba, Yoshitaka Kawasugi, Reizo Kato, and Naoya Tajima, J. Phys. Soc. Jpn., 92, (2023) 053701/1-5.


  9. "Chasing the spin gap through the phase diagram of a frustrated Mott insulator"
    Andrej Pustogow, Yoshitaka Kawasugi, Hirohito Sakurakoji, and Naoya Tajima, Nat. Commun., 14, (2023) 1960/1-6.


  10. "Strain-induced massless Dirac fermion state of the molecular conductor α-(BEDT-TTF)2I3"
    Yoshitaka Kawasugi, Haruto Suzuki, Hiroshi M. Yamamoto, Reizo Kato, and Naoya Tajima, Appl. Phys. Lett., 122, (2023) 123102/1-4.

  11. "Coherent Interlayer Coupling in Quasi-Two-Dimensional Dirac Fermions in α-(BEDT-TTF)2I3"
    Naoya Tajima, Yoshitaka Kawasugi, Takao Morinari, Ryuhei Oka, Toshio Naito, Reizo Kato, J. Phys. Soc. Jpn., 92, (2022) 013702/1-2.

  12. "Narrow Zero Mode in Organic Massless Dirac Fermion System a-(BEDT-TTF)2I3"
    A. Mori, Y. Kawasugi, R. Doi, T. Naito, R. Kato, Y. Nishio, and N. Tajima, J. Phys. Soc. Jpn., 91 (2022) 045001-1-2.

  13. “Large Diamagnetism and Electromagnetic Duality in Two-Dimensional Dirac Electron System":
    S. Fujiyama, H. Maebashi, N. Tajima, T. Tsumuraya, H-B. Cui, M. Ogata,and R. Kato
    Phys. Rev. Lett., 128 (2022) 027201-1-5.

  14. "Simultaneous Control of Bandfilling and Bandwidth in Electric Double-Layer Transistor Based on Organic Mott Insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl" Y. Kawasugi and H. M. Yamamoto, Crystals, 12 (2022) 42/1-15.

  15. "Electric Double Layer Doping of Charge-Ordered Insulators α-(BEDT-TTF)2I3 and α-(BETS)2I3"
    Y. Kawasugi et al., Crystals, 11 (2021) 791/1-10.
    DOI: https://doi.org/10.3390/cryst11070791

  16. "Pressure-induced phase switching of Shubnikov-de Haas oscillations in the molecular Dirac fermion system α-(BETS)2I3"
    Y. Kawasugi et al., Phys. Rev. B, 103 (2021) 205140/1-6.
    DOI: https://doi.org/10.1103/PhysRevB.103.205140

  17. “High-Pressure Crystal Structure and Unusual Magnetoresistance of a Single-Component Molecular Conductor [Pd(dddt)2] (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolate)":
    H. Cui, H. H.-M. Yeung, Y. Kawasugi, T. Minamidate, L. K. Saunders, and R. Kato
    Crystals, 11 (2021) 534/1-19.
    DOI: https://doi.org/10.3390/cryst11050534

  18. “No Mass Gap Phase Transition in Novel Massless Dirac Fermion Material":
    JPS Hot Topics, 1 (2021) 023.
    DOI: https://doi.org/10.7566/JPSHT.1.023

  19. “Unusual stoichiometry, band structure and band filling in conducting enantiopure radical cation salts of TM-BEDT-TTF showing helical packing of the donors":
    F. Pop, C. Meziere, M. Allain, P. Auban-Senzier, N. Tajima, D. Hirobe, H. M. Yamamoto, E. Canadell, and N. Avarvari
    Journal of Materials Chemistry C, (2021).
    DOI: 10.1039/d1tc01112j

  20. “Quantum Phase Transition in Organic Massless Dirac Fermion System a-(BEDT-TTF)2I3 under Pressure":
    R. Unozawa, Y. Kawasugi, M. Suda, H. M. Yamamoto, R. Kato, Y. Nishio, K. Kajita, T. Morinari, and N. Tajima
    J. Phys. Soc. Jpn., 89 (2020) 123702-1-5. Ediotrs' Choice

  21. “Universal Behavior of Magnetoresistance in Organic Dirac Electron Systems":
    R. Kobara, S. Igarashi, Y. Kawasugi, R. Doi, T. Naito, M. Tamura, R. Kato, Y. Nishio, K. Kajita, and N. Tajima
    J. Phys. Soc. Jpn., 89 (2020) 113704-1-4.

  22. “ Non-Fermi-liquid Behavior and Doping Asymmetry in an Organic Mott Insulator Interface”:
    Y. Kawasugi, K. Seki, J. Pu, T. Takenobu, S. Yunoki, H. M. Yamamoto, and Reizo Kato
    Phys. Rev. B, 100 (2019) 115141-1-7.

  23. “ Two-Dimensional Ground-State Mapping of a Mott-Hubbard System in a Flexible Field-Effect Device”:
    Y. Kawasugi, K. Seki, S. Tajima, J. Pu, T. Takenobu, S. Yunoki, H. M. Yamamoto, and Reizo Kato
    Sci. Adv., 5 (2019) eaav7282-1-9.

  24. “ Field-Angle Dependence of Interlayer Magnetoresistance in Organic Dirac Electron System a-(BEDT-TTF)2I3”:
    T. Tani, N. Tajima, and A. Kobayashi
    Crystals, 9 (2019) 212-1-11.

  25. “Effects of Carrier Doping on the Transport in the Dirac Electron System a-(BEDT-TTF)2I3 underHigh Pressure”:
    N. Tajima
    Crystals, 8 (2018) 126-1-17.

  26. “Tilted Dirac Cone Effect on Interlayer Magnetoresistance in a-(BEDT-TTF)2I3”:
    N. Tajima, and T. Morinari
    J. Phys. Soc. Jpn., 87 (2018) 045002-1-2.

  27. “Magnetocaloric Effect in Layered Organic Conductor l-(BETS)2FeCl4”:
    S. Sugiura, K. Shimada, N. Tajima, Y. Nishio, T. Terashima, T. Isono, R. Kato, B. Zhou, and Shinya Uji
    J. Phys. Soc. Jpn., 87 (2018) 044601-1-6.

  28. “Slow dynamics of electrons at a metal?Mott insulator boundary in an organic system with disorder”:
    T. Itou, E. Watanabe, S. Maegawa, A. Tajima, N. Tajima, K. Kubo, R. Kato, K. Kanoda
    Sci. Adv., 3 (2017) e1601594-1-6.

  29. “Magnetic Torque Studies in Two-Dimensional Organic Conductor l-(BETS)2FeCl4”:
    S. Sugiura, K. Shimada, N. Tajima, Y. Nishio, T. Terashima, T. Isono, R. Kato, and S. Uji
    J. Phys. Soc. Jpn., 86 (2017) 014702.

  30. “Aperiodic quantum oscillations of particle-hole asymmetric Dirac cones”:
    E. Tisserond, J. N. Fuchs, M. O. Goerbig, P. Auban-Senzier, C. M´ezi`ere, P. Batail, Y. Kawasugi, M. Suda, H. M. Yamamoto, R. Kato, N. Tajima and M. Monteverde
    EPL, 119 (2017) 67001.

  31. “Charge Transport in Antiferromagnetic Insulating Phase of Two-Dimensional Organic Conductor l-(BETS)2FeCl4”:
    S. Sugiura, K. Shimada, N. Tajima, Y. Nishio, T. Terashima, T. Isono, A. Kobayashi, B. Zhou, R. Kato, and S. Uji
    J. Phys. Soc. Jpn., 85 (2016) 064703.

  32. “Effective Field Study of Canted Antiferromagnetic Insulating Phase in Magnetic Organic Conductor l-(BETS)2FeCl4 through Specific Heat Measurement”:
    K. Shimada, N. Tajima, K. Kajita, and Y. Nishio
    J. Phys. Soc. Jpn., 85 (2016) 023601.

  33. “Universality class of the Mott-Hubbard transition”:
    M. Abdel-Jawad, R. Kato, I. Watanabe, N. Tajima, and Y. Ishii
    Phys. Rev. Lett., 114 (2015) 106401.

  34. “Nonlinear photocurrent with threshold of excitation density induced by long-range electron--electron interaction in a charge-ordered molecular conductor (BEDT-TTF)3(ClO4)2”:
    N. Takubo, N. Tajima, H. M. Yamamoto and R. Kato
    J. Phys.: Condens. Matter, 26 (2014) 055603.

  35. “Thermoelectric power of multilayered massless Dirac fermion system a-(BEDT-TTF)2I3 -Charge ordering and zero-gap states-”:
    R. Kitamura, N. Tajima, K. Kajita, R. Kato, M. Tamura, T. Naito and Y. Nishio
    JPS Conf. Proc., 1 (2014) 012097.

  36. “Temperature dependence of internal field by analysis of specific heat on an organic conductor l-BETS2FeCl4 ”:
    K. Shimada, H. Akiba, N. Tajijma, K. Kajita, Y. Nishio, R. Kato, A. Kobayashi and H. Kobayashi
    JPS Conf. Proc., 1 (2014) 012110.

  37. “Molecular Dirac Fermion System -Theoretical and Experimental Approach-”:
    K. Kajita, Y. Nishio, N. Tajima, Y. Suzumura, and A. Kobayashi
    J. Phys. Soc Jpn., 83 (2014) 072002. Invited paper

  38. “Reentrant Metal-Insulator-Metal Transition in (DMe-DCNQI)2Cu System - Competition between Spin and Free Electron Degrees of Freedom-”:
    Y. Nishio, N. Tajima, and K. Kajita,
    Current Inorganic Chemistry, 4 (2014) 110. Review paper

  39. “Observation of photo-induced insulator-to-metal transition in charge-ordered a-(BEDT-TTF)2I3 thin crystal by simultaneous transport and optical measurement”
    N. Takubo, N. Tajima, H.M. Yamamoto, and R. Kato
    Journal of Luminescence 137 (2013) 237

  40. “Bilayer Mott System with Cation…Anion Supramolecular Interactions Based on a Nickel Dithiolene Anion Radical: Coexistence of Ferro- and Antiferromagnetic Anion Layers and Large Negative Magnetoresistance”
    T. Kusamoto, H. M. Yamamoto, N. Tajima, Y. Oshima, S. Yamashita, and R. Kato
    Inorg. Chem., 52 (2013) 4759.

  41. “Photoinduced metal-insulator phase transition in the charge-ordered organic salts (BEDT-TTF)3X2 (X = ReO4, ClO4) is stabilized by lattice distortions”
    N. Takubo, N. Tajima, H. Cui, R. Kato, and H. M. Yamamoto
    Phys. Rev. Lett., 110 (2013) 227401.

  42. “Disordered conduction in single-crystalline dimer Mott compounds”:
    M. Abdel-Jawad, N. Tajima, R. Kato, and I. Terasaki
    Phys. Rev. B 88 (2013) 075139.

  43. “Quantum Hall Effect in Molecular Dirac Fermion Systems with Tilted Cones”:
    N. Tajima, T. Yamauchi, T. Yamaguchi, M. Suda, Y. Kawasugi, H. M. Yamamoto, R. Kato, Y. Nishio, and K. Kajita
    Phys. Rev. B 88 (2013) 075315.

  44. “Interband effects of magnetic field on Hall conductivity in the multilayered massless Dirac fermion system a-(BEDT-TTF)2I3”:
    N. Tajima, R. Kato, S. Sugawara, Y. Nishio, and K. Kajita,
    Phys. Rev. B, 85 (2012) 033401-1-4.

  45. “Transport Phenomena in Multilayered Massless Dirac Fermion System a-(BEDT-TTF)2I3”:
    N. Tajima, Y. Nishio, and K. Kajita,
    Crystals, 2 (2012) 643-661. Review

  46. “Paramagnetic Metal-Antiferromagnetic Insulator Transition in π-d System l-BETS2FeCl4, BETS = Bis(ethylenedithio)tetraselenafulvalene”:
    H. Akiba, K. Shimada, N. Tajima, K. Kajita, and Y. Nishio,
    Crystals, 2 (2012) 984-995. Review

  47. “Paramagnetic Metal-Antiferromagnetic Insulator Transition of λ-BETS2FexGa1-xCl4 System”:
    H. Akiba, H. Sugawara, K.Nobori, K. Shimada, N. Tajima, Y. Nishio, K. Kajita, B. Zhou, A. Kobayashi, and H. Kobayashi,
    J. Phys. Soc Jpn., 81 (2012) 053651-1-3.

  48. “Bilayer Mott System Based on Ni(dmit)2 (dmit = 1,3-dithiole-2-thione-4,5-dithiolate) Anion Radicals: Two Isostructural Salts Exhibit Contrasting Magnetic Behavior”:
    T. Kusamoto, H. M. Yamamoto, N. Tajima, Y. Oshima, S. Yamashita, and R. Kato,
    Inorg. Chem., 51 (2012) 11645-11654.

  49. “Temperature Dependence of Inter-Layer Longitudinal Magnetoresistance in a-(BEDT-TTF)2I3: Positive versus Negative Contributions in a Tilted Dirac Cone System・Eh:
    S. Sugawara, M. Tamura, N. Tajima, M. Sato, R. Kato, Y. Nishio and K. Kajita,
    J. Phys. Soc. Jpn.., 79 (2010) 113704-1-4. Editor’s Choice

  50. “Spin and Valley Splittings in Multilayered Massless Dirac Fermion System”:
    N. Tajima, M. Sato, S. Sugawara, R. Kato, Y. Nishio and K. Kajita,
    Phys. Rev. B., 82 (2010) 121420-1-4.

  51. “Transport Phenomenon of Multilayer Zero-Gap Conductor in the Quantum Limit”:
    M. Sato, K. Miura, S. Endo, S. Sugawara, N. Tajima, K. Murata, Y. Nishio and K. Kajita,
    J. Phys. Soc. Jpn.., 80 (2011) 023706-1-4.

  52. “Local Spin Susceptibility of a-D2I3 (D = bis(ethylendithio)tetraselenafulvalene (BETS) and bis(ethylendithio)dithiadiselenafulvalene (BEDT-STF)) Studied by 77Se NMR”:
    K. Hiraki, S. Harada, K. Arai, Y. Takano, T. Takahashi, N. Tajima, R. Kato and T. Naito,
    J. Phys. Soc. Jpn.., 80 (2011) 014715-1-5.

  53. “Electric-field-induced Mott transition in an organic molecular crystal”:
    Y. Kawasugi, H. M. Yamamoto, N. Tajima, T. Fukunaga, K. Tsukagoshi and R. Kato,
    Phys. Rev. B., 82 (2011) 125129-1-9. Editor’s Suggestions


[解説]
  1. “有機固体におけるディラック電子と磁場効果”:
    田嶋尚也,
    パリティ 26 (2011) p27-29.

  2. “分子性ゼロギャップ電気伝導体の発見”:
    田嶋尚也
    科研費ニュース2011-12 No. 4, 21.

  3. “ディラック電子系分子性導体への静電キャリア注入を目的とした電界効果トランジスタの作製および物性評価”:
    田嶋尚也
    分子研レターズ 69 (2014) p40-42.

  4. “有機ディラック電子系における量子ホール状態”:
    田嶋尚也、 佐藤光幸、鴻池貴子、長田俊人
    固体物理 49 (2014) p229-240.

  5. “バンド幅とバンドフィリングの同時制御による分子性モット絶縁体の2次元超伝導相図”:
    川椙義高、関 和弘、柚木清司、山本浩史
    固体物理 56 (2021) p21-31.

  6. “質量のない電子の不思議な量子相転移”:
    田嶋尚也、森成隆夫
    固体物理 56 (2021) p553-544.

  7. “歪み制御型電界効果トランジスタを用いた分子性導体における超伝導の探索”:
    川椙義高、須田理行、山本浩史
    高圧力学会誌, 31 (2021) 193-202.

  8. “バルクな有機結晶で実現する対称性が破れた量子ホール状態”:
    田嶋尚也、川椙義高
    固体物理 58 (2023) p789-802.


[著書]
  1. 日本化学会編　"第5版　実験化学講座　7巻"　(電気物性、磁気物性)(丸善)-- 4 種々の輸送現象 (4.1ホール効果, 4.2磁気抵抗)

  2. “薄膜の評価技術ハンドブック”　(第II部基本物性測定)(株テクノシステム)-- 7 有機薄膜の物性評価

  3. “分子性物質の物理　物性物理の新潮流” (朝倉商店)-- 第6章 質量のないディラック電子

東邦大学理学部物理学科
物性物理学教室
〒274-8510
千葉県船橋市三山2-2-1

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