Publications
>>English
Since 7. 2007
    論文リスト (太字: 重要な結果)

    1. Charge fractionalization in artificial Tomonaga-Luttinger liquids with controlled interaction strength
      Paul Brasseur, Ngoc Han Tu, Yoshiaki Sekine, Koji Muraki, Masayuki Hashisaka, Toshimasa Fujisawa, and Norio Kumada
      Phys. Rev. B 96, 081101(R) (2017).

    2. Quantum Hall effect in epitaxial graphene with permanent magnets
      F. D. Parmentier, T. Cazimajou, Y. Sekine, H. Hibino, H. Irie, D. C. Glattli, N. Kumada, and P. Roulleau
      Scientific Reports 6, 38393 (2016).

    3. Andreev reflection and bound state formation in a ballistic two-dimensional electron gas probed by a quantum point contact
      Hiroshi Irie, Clemens Todt, Norio Kumada, Yuichi Harada, Hiroki Sugiyama, Tatsushi Akazaki, and Koji Muraki
      Phys. Rev. B 94, 155305 (2016).

    4. Evaluation of Disorder Introduced by Electrolyte Gating through Transport Measurements in Graphene
      Andrew Browning, Norio Kumada, Yoshiaki Sekine, Hiroshi Irie, Koji Muraki, and Hideki Yamamoto
      Appl. Phys. Express 9, 065102 (2016).

    5. グラフェンp-n接合を用いた電子のビームスプリッタ動作の原理実証に世界で初めて成功
      熊田倫雄
      電子情報通信学会誌ニュース解説 Vol.99 No.3 266 (2016).

    6. Shot noise generated by graphene p-n junctions in the quantum Hall effect regime
      N. Kumada, F. D. Parmentier, H. Hibino, D. C. Glattli, and P. Roulleau
      Nature Commun. 6, 8068 (2015).

    7. Resonant Edge Magnetoplasmons and Their Decay in Graphene
      N. Kumada, P. Roulleau, B. Roche, M. Hashisaka, H. Hibino, I. Petkovic, and D. C. Glattli
      Phys. Rev. Lett. 113, 266601 (2014).

    8. Effects of screening on the propagation of graphene surface plasmons
      Ken-ichi Sasaki and Norio Kumada
      Phys. Rev. B 90, 035449 (2014).

    9. Plasmon transport and its guiding in graphene
      Norio Kumada, Romain Dubourget, Ken'ichi Sasaki, Shinichi Tanabe, Hiroki Hibino, Hiroshi Kamata, Masayuki Hashisaka, Koji Muraki, Toshimasa Fujisawa
      New J. Phys. 16, 063055 (2014).

    10. 量子ホール端における電荷密度波のダイナミクス
      橋坂昌幸、鎌田大、藤澤利正、熊田倫雄、村木康二
      個体物理 Vol.49 No.5 359 (2014).

    11. Fractionalized wave packets from an artificial Tomonaga-Luttinger liquid
      H. Kamata, N. Kumada, M. Hashisaka, K. Muraki, and T. Fujisawa,
      Nature Nanotech. 9, 177 (2014).

    12. グラフェンを用いたプラズモン伝搬制御
      熊田 倫雄、田邉 真一、村木 康二、藤澤 利正
      応用物理学会誌12月号

    13. Distributed-element circuit model of edge magnetoplasmon transport
      Masayuki Hashisaka, Hiroshi Kamata, Norio Kumada, Kazuhisa Washio, Ryuji Murata, Koji Muraki, and Toshimasa Fujisawa
      Phys. Rev. B 88, 235409 (2013).

    14. Tunable plasmons in graphene
      N. Kumada, S. Tanabe, H. Hibino, H. Kamata, M. Hashisaka, K. Muraki, and T. Fujisawa
      SPIE Newsroom

    15. Plasmon Transport in Graphene
      Norio Kumada
      NTT Technical Review August 2013 Vol. 11 No. 8

    16. グラフェン中のプラズモン伝導
      熊田倫雄
      NTT技術ジャーナル 6月号 19 (2013).

    17. Plasmon transport in graphene investigated by time-resolved electrical measurements
      N. Kumada, S. Tanabe, H. Hibino, H. Kamata, M. Hashisaka, K. Muraki, and T. Fujisawa
      Nature Commun. 4, 1363 (2013).

    18. All electrical probe of nuclear spin polarization and relaxation by spin phase transition peaks of the filling fraction nu=2/3 quantum hall effect
      M. H. Fauzi, S. Watanabe, N. Kumada, and Y. Hirayama
      J. Korean Physical Soc. 60, 1676 (2012).

    19. Unraveling the Spin Polarization of the nu = 5/2 Fractional Quantum Hall State
      L. Tiemann, G. Gamez, N. Kumada, and K. Muraki
      Science 335, 828 (2012).

    20. Low-frequency spin fluctuations in skyrmions confined by wires: Measurements of local nuclear spin relaxation
      Takashi Kobayashi, Norio Kumada, Takeshi Ota, Satoshi Sasaki, and Yoshiro Hirayama
      Phys. Rev. Lett. 107, 126807 (2011).

    21. Edge magnetoplasmon transport in gated and ungated quantum Hall systems
      N. Kumada, H. Kamata, and T. Fujisawa
      Phys. Rev. B 84, 045314 (2011).

    22. Dynamical d-wave condensation of exciton-polaritons in a two-dimensional square-lattice potential
      Na Young Kim, Kenichiro Kusudo, Congjun Wu, Naoyuki Masumoto, Andreas Löffler, Sven Höfling, Norio Kumada, Lukas Worschech, Alfred Forchel, and Yoshihisa Yamamoto
      Nature Phys. 7, 681 (2011).

    23. Field and Density Dependence of Edge Magnetoplasmon Transport in a Quantum Hall System
      N. Kumada, H. Kamata, K. Muraki, and T. Fujisawa
      J. Phys.: Conf. Ser. 334 012032 (2011).

    24. High-sensitive optical measurement of spin polarization in a quantum Hall system
      H. Ito, T. Yamazaki, D. Fukuoka, K. Oto, K. Muro, Y. Hirayama, and N. Kumada
      J. Phys.: Conf. Ser. 334 012021 (2011).

    25. Spin polarization in quantum Hall state obtained by Kerr rotation spectra
      H. Ito, M. Seo, D. Fukuoka, K. Oto, K. Muro, Y. Hirayama, and N. Kumada
      AIP Conf. Proc. 1399, 637 (2011).

    26. Anisotropy of Magnetoresistance Hysteresis around the nu=2/3 Quantum Hall State in Tilted Magnetic Field
      K. Iwata, M. Morino, A. Fukuda, N. Kumada, Z. F. Ezawa, Y. Hirayama, and A. Sawada
      J. Phys. Soc. Jpn. 79, 123701 (2010).

    27. Skyrmion effect on the relaxation of spin waves in a quantum Hall ferromagnet
      D. Fukuoka, K. Oto, K. Muro, Y. Hirayama, and N. Kumada
      Phys. Rev. Lett. 105, 126802 (2010).

    28. Nuclear spin polarization and relaxation probed by spin phase transition peak
      S. Watanabe, M. H. Fauzi, N. Kumada, and Y. Hirayama
      Phys. Status Solidi C 7, 2570 (2010).

    29. Activation study of collective excitations of the soliton-lattice phase in the nu=1 double-layer quantum Hall state
      D. Terasawa, S. Kozumi, A. Fukuda, M. Morino, K. Iwata, N. Kumada, Y. Hirayama, Z. F. Ezawa and A. Sawada
      Phys. Rev. B 81, 073303 (2010).

    30. Intrinsic gap and exciton condensation in the nu_T=1 bilayer system
      P. Giudici, K. Muraki, N. Kumada, and T. Fujisawa
      Phys. Rev. Lett. 104, 056802 (2010).
      >>abstract

    31. Spectroscopic study of nuclear magnetic resonance induced by oscillating electron spin domain walls
      S.Watanabe, G.Igarashi, K. Hashimoto, N.Kumada, and Y. Hirayama
      Physica E 42, 999 (2010).

    32. Nuclear Spin Resonance Induced by Radio Frequency Electric Field
      N. Kumada, T. Kamada, Y. Hirayama, S. Miyashita, and T. Fujisawa
      AIP Conf. Proc. 1199, 461 (2010).

    33. Selective polarization of nuclear spins in a wire-like quantum Hall system
      T. Kobayashi, N. Kumada, T. Ota, S. Sasaki and Y. Hirayama
      AIP Conf. Proc. 1199, 241 (2010).

    34. Time-Resolved Kerr Rotation Spectroscopy of Spin Dynamics in a Quantum Hall System
      D. Fukuoka, N. Tanaka, K. Oto, K. Muro, Y. Hirayama, N. Kumada, and H. Yamaguchi
      AIP Conf. Proc. 1199, 243 (2010).

    35. Spin effects in the phase transition of the nu_T=1 bilayer electron system
      K. Muraki, P. Giudici, and N. Kumada
      Int. J. Mod. Phys. B 23, 2587 (2009).

    36. Electron spin imaging in quantum Hall devices by Kerr rotation measurement
      K. Oto ,R. Inaba, T. Yamada, T. Yamazaki, K. Muro, Y. Hirayama, N. Kumada and H. Yamaguchi
      Int. J. Mod. Phys. B 23, 2705 (2009).

    37. Optically induced nuclear spin polarization in quantum Hall regime observed by a time-resolved Kerr rotation
      D. Fukuoka, N. Tanaka, K. Oto, K. Muro, Y. Hirayama, N. Kumada, H. Yamaguchi
      Int. J. Mod. Phys. B 23, 2755 (2009).

    38. Activation study of the pseudospin soliton in the nu=1 bilayer quantum Hall effect
      A. Fukuda, D. Terasawa, M. Morino, K. Iwata, S. Kozumi, T. Sekikawa, Y. Ogasawara, T. Arai, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      J. Phys.: Conf. Ser. 150, 022012 (2009).

    39. Electron-spin/nuclear-spin interactions and NMR in semiconductors
      Y. Hirayama, G. Yusa, K. Hashimoto, N. Kumada, T. Ota, and K. Muraki
      Semicond. Sci. Technol. 24, 023001 (2009).
      Semiconductor Science & Technology Highlights of 2009

    40. Electric-Field-Induced Nuclear Spin Resonance Mediated by Oscillating Electron Spin Domains in GaAs-Based Semiconductors
      N. Kumada, T. Kamada, S. Miyashita, Y. Hirayama, T. Fujisawa
      Phys. Rev. Lett. 101, 137602 (2008).
      >>abstract

    41. Observation of Bogoliubov excitations in exciton-polariton condensates
      S. Utsunomiya, L. Tian, G. Roumpos, C. W. Lai, N. Kumada, T. Fujisawa, M. Kuwata-Gonokami, A. Loffler, S. Hofling, A. Forchel, and Y. Yamamoto
      Nature Physics 4, 700 (2008).
      >>abstract

    42. Spin Dynamics of Two-Dimensional Electrons in a Quantum Hall System Probed by Time-Resolved Kerr Rotation Spectroscopy
      D. Fukuoka, T. Yamazaki, N. Tanaka, K. Oto, K. Muro, Y. Hirayama, N. Kumada, and H. Yamaguchi
      Phys. Rev. B 78, 041304(R) (2008).
      >>abstract

    43. GaAs microcavity exciton-polaritons in a trap
      Na Young Kim, Chih-Wei Lai, Shoko Utsunomiya, Georgios Roumpos, Hui Deng, Tim Byrnes, Patrik Recher, Norio Kumada, Toshimasa Fujisawa, and Yoshihisa Yamamoto
      Phys. Stat. Sol. (b) 245, 1076 (2008).

    44. Modulation of bilayer quantum Hall states by tilted-field-induced subband-Landau-level coupling
      N. Kumada, K. Iwata, K. Tagashira, Y. Shimoda, K. Muraki, Y. Hirayama, and A. Sawada
      Phys. Rev. B. 77, 155324 (2008).
      >>abstract

    45. Boundary-mediated electron-electron interactions in quantum point contacts
      V. T. Renard, O. A. Tkachenko, V. A. Tkachenko, T. Ota, N. Kumada, J-C Portal, and Y. Hirayama
      Phys. Rev. Lett. 100, 186801 (2008).
      >>abstract

    46. Spin-dependent phase diagram of the nu_T=1 bilayer electron system
      P. Giudici, K. Muraki, N. Kumada, Y. Hirayama, and T. Fujisawa
      Phys. Rev. Lett. 100, 106803 (2008).
      >>abstract

    47. NMR Study of a Canted Antiferromagnet in a Bilayer Quantum Hall System
      N. Kumada, K. Muraki, and Y. Hirayama
      Physica E 40, 937 (2008).

    48. Electron-electron interactions in clean quantum point contacts in the large conductance regime
      V. T. Renard, O. A. Tkachenko, V. A. Tkachenko, T. Ota, N. Kumada, J. C. Portal, and Y. Hirayama
      Physica E 40, 1684 (2008).

    49. Effects of In-plane Magnetic Field Direction on the Nuclear Spin Relaxation in the nu=2/3 Quantum Hall State
      K. Iwata, M. Moriono, A. Fukuda, A. Sawada, M. Suzuki, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      Physica E 40, 1175 (2008).

    50. Anisotropic Magnetotransport by the Psudospin Soliton in the Bilayer nu=1 Quantum Hall System
      A. Fukuda, M. Morino, K. Iwata, D. Terasawa, S. Kozumi, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      Physica E 40, 1255 (2008).

    51. Activation Study of the Bilayer nu=1/3 Quantum Hall State
      A. Fukuda, K. Iwata, T. Sekikawa, T. Arai, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      Physica E 40, 1261 (2008).

    52. Initialization and logic gate operations of nuclear spin qubits using a submicron scale resistively-detected NMR device
      T. Ota, G. Yusa, N. Kumada, S. Miyashita, and Y. Hirayama
      Phys. Stat. Sol. (c) 5, 306 (2008).

    53. Nuclear-spin-based Quantum Information Devices in Solid-State Nanometer-Scale Structures
      Norio Kumada, Takeshi Ota, and Koji Muraki
      NTT Technical Review January 2008 Vol. 6 No. 1

    54. Coherence Time of Nuclear Spins in GaAs Quantum Well Probed by Submicron-Scale All-Electrical Nuclear Magnetic Resonance Device
      Takeshi Ota, Norio Kumada, Go Yusa, Sen Miyashita, Toshimasa Fujisawa, and Yoshiro Hirayama
      Jpn. J. Appl. Phys. 47, 3115 (2008).

    55. Pseudospin soliton in the nu=1 bilayer quantum Hall state
      A. Fukuda, D. Terasawa, M. Morino, K. Iwata, S. Kozumi, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      Phys. Rev. Lett. 100, 016801 (2008).
      >>abstract

    56. Positive magneto-resistance in a point contact: possible manifestation of interactions
      V. T. Renard, T. Ota, N. Kumada, and Y. Hirayama
      International Journal of High Speed Electronics and Systems 17, 495 (2007).

    57. 固体ナノ構造における核スピン量子情報デバイス
      熊田倫雄、太田剛、村木康二
      NTT技術ジャーナル 11月号 14 (2007).

    58. Decoherence of nuclear spins due to dipole-dipole interactions probed by resistively detected nuclear magnetic resonance
      T. Ota, G. Yusa, N. Kumada, S. Miyashita, T. Fujisawa, and Y. Hirayama
      Appl. Phys. Lett. 91, 193101 (2007).
      >>abstract

    59. Coherent zero-state and pi-state in an exciton-polariton condensate array
      C. W. La, N. Y. Kim, S. Utsunomiya, G. Roumpos, H. Deng, M. D. Fraser, T. Byrnes, P. Recher, N. Kumada, T. Fujisawa, and Y. Yamamoto
      Nature 450, 529 (2007).
      >>abstract

    60. NMRによる量子ホール傾角反強磁性状態におけるゴールドストーンモードの観測
      熊田倫雄、村木康二、平山祥郎
      固体物理 Vol.42 No.9 551 (2007).

    61. NMR Evidence for Spin Canting in a Bilayer nu=2 Quantum Hall System
      N. Kumada, K. Muraki, and Y. Hirayama
      Phys. Rev. Lett. 99, 076805 (2007).
      >>abstract

    62. Anisotropy of Current-pumped Nuclear Spin Polarization in the nu=2/3 Quantum Hall State
      K. Iwata, M. Moriono, A. Fukuda, A. Sawada, M. Suzuki, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      AIP Conference Proceedings 893, 643 (2007).

    63. Effects of In-plane Magnetic Fields on the Canted Antiferromagnetic Phase in the Bilayer nu=2 Quantum Hall State
      A. Fukuda, S. Kozumi, D. Terasawa, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      AIP Conference Proceedings 893, 639 (2007).

    64. Interaction of Electron and Nuclear Spins in Quantum Wells
      K. Muraki, N. Kumada, and Y. Hirayama
      Int. J. Mod. Phys. B 21, 1266 (2007).

    65. Nuclear spin population and its control toward initialization using an all-electrical sub-micron scale nuclear magnetic resonance device
      T. Ota, G. Yusa, N. Kumada, S. Miyashita, and Y. Hirayama
      Appl. Phys. Lett. 90, 102118 (2007).
      >>abstract

    66. Study of nuclear quadrupolar interaction using a novel all-electrical GaAs NMR device
      T. Ota, N. Kumada, G. Yusa, S. Miyashita, and Y. Hirayama
      Phys. Stat. Sol. (c) 4, 1759 (2007).

    67. In-plane Field Induced Anisotropic Behavior of Hysteresis in the nu=2/3 Quantum Hall State
      K. Iwata, A. Fukuda, A. Sawada, M. Moriono, Z. F. Ezawa, M. Suzuki, N. Kumada, and Y. Hirayama
      Proceedings of MS+S

    68. Phase Diagram of the nu=2 Bilayer Quantum Hall State
      A. Fukuda, A. Sawada, K. Iwata, S. Kozumi, D. Terawasa, Y. Shimoda, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      Proceedings of MS+S

    69. Low-Frequency Spin Dynamics in a Canted Antiferromagnet
      N. Kumada, K. Muraki, and Y. Hirayama
      Science 313, 329 (2006).
      >>abstract

    70. Nuclear-spin-lattice relaxation in a nu=1 bilayer quantum Hall state
      N. Kumada, K. Muraki, and Y. Hirayama
      Physica E 34, 164 (2006).

    71. Anisotropic magnetotransport near the nu=2/3 quantum Hall state
      M. Morino, K. Iwata, M. Suzuki, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      Physica E 34, 152 (2006).

    72. Stability of Soliton Lattice phase in the nu=1 Bilayer Quantum Hall State under Tilted Magnetic Fields
      D. Terasawa, A. Fukuda, S. Kozumi, Z. F. Ezawa, A. Sawada, N. Kumada, and Y. Hirayama
      Physica E 34, 81 (2006).

    73. Quantum Transport Study of a Canted Antiferromagnetic Phase in nu=2 Bilayer Quantum Hall State
      A. Fukuda, S. Kozumi, D. Terasawa, Y. Shimoda, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      Physica E 34, 77 (2006).

    74. Magnetotransport Study of the Canted Antiferromagnetic Phase in Bilayer nu=2 Quantum Hall State
      A. Fukuda, S. Kozumi, D. Terasawa, Y. Shimoda, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      Phys. Rev. B 73, 165304 (2006).

    75. Magnetoresistance Peak in the nu=2 Bilayer Quantum Hall State under Tilted Magnetic Field
      A. Fukuda, S. Kozumi, D. Terasawa, N. Kumada, Y. Hirayama, Z. F. Ezawa, and A. Sawada
      AIP Conference Proceedings 850, LT24, 1337 (2006).

    76. Anisotropic behavior of hysterestic transport phenomena in the nu=2/3 quantum Hall state in the tilted magnetic field
      K. Iwata, M. Morino, A. Fukuda, A. Sawada, Z. F. Ezawa, M. Suzuki, N. Kumada, and Y. Hirayama
      AIP Conference Proceedings 850, LT24, 1339 (2006).

    77. Anisotropic Magnetotransport Near The Bilayer nu=2/3 Quantum Hall State
      M. Morino, K. Iwata, M. Suzuki, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      AIP Conference Proceedings 850, LT24, 1335 (2006).

    78. Effects of inversion asymmetry on electron-nuclear spin coupling in semiconductor heterostructures: A possible role of spin-orbit interactions
      K. Hashimoto, K. Muraki, N. Kumada, and Y. Hirayama
      Phys. Rev. Lett. 94, 146601 (2005).
      >>abstract

    79. Pseudospin domain of nu=1 double-layer quantum Hall state near commensurate-incommensurate transition
      D. Terasawa, S. Kozumi, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      Journal of Physics and Chemistry of Solids 66, 1560 (2005).

    80. Anisotropic magnetotransport around the nu=1 bilayer quantum Hall state
      K. Iwata, M. Morino, M. Suzuki, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, and Y. Hirayama
      Journal of Physics and Chemistry of Solids 66, 1556 (2005).

    81. Spin degree of freedom in the nu=1 bilayer electron system investigated by nuclear spin relaxation
      N. Kumada, K. Muraki, K. Hashimoto, and Y. Hirayama
      Phys. Rev. Lett. 94, 096802 (2005).
      >>abstract

    82. Strong to weak correlation phase transition at nu_T=1 in a bilayer system detected by nuclear-spin-relaxation time
      N. Kumada, K. Muraki, K. Hashimoto, T. Saku, and Y. Hirayama
      AIP Conf. Proc. 772 567 (2005).

    83. Double magnetoresistance minima for nu=1 quantum Hall state near commensurate-incommensurate transition
      D. Terasawa, K. Nakada, S. Kozumi, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, K. Muraki, T. Saku, and Y. Hirayama
      AIP Conf. Proc. 772 563 (2005).

    84. In-plane filed induced anisotropy of the longitudinal resistance in a bilayer quantum Hall system
      M. Morino, K. Iwata, M. Suzuki, A. Fukuda, A. Sawada, Z. F. Ezawa, N. Kumada, K. Muraki, T. Saku, and Y. Hirayama
      AIP Conf. Proc. 772 565 (2005).

    85. Duoble magnetoresistance minima induced by the in-plane magnetic field for the nu=1 double-layer quantum Hall st ate
      D. Terasawa, K. Nakada, S. Kozumi, Z. F. Ezawa, A. Fukuda, A. Sawada, N. Kumada, K. Muraki, T. Saku, and Y. Hirayama
      Int. J. Mod. Phys. B 18, 3709 (2004).

    86. Anisotropic transport on the nu=1 bilayer quantum Hall system under tilted magnetic filed
      M. Morino, K. Iwata, M. Suzuki, Z. F. Ezawa, A. Sawada, N. Kumada, K. Muraki, T. Saku, and Y. Hirayama
      Int. J. Mod. Phys. B 18, 3705 (2004).

    87. Phase diagrams of nu=2 and nu=2/3 quantum Hall states in bilayer systems
      N. Kumada, D. Terasawa, M. Morino, K. Tagashira, A. Sawada, E. F. Ezawa, K. Muraki, Y. Hirayama and T. Saku
      Phys. Rev. B 69, 155319 (2004).
      >>abstract

    88. Simultaneous excitation of spins and pseudospins in the bilayer nu=1 quantum hall state
      D. Terasawa, M. Morino, K. Nakada, S. Kozumi, A. Sawada, Z. F. Ezawa, N. Kumada, K. Muraki, T. Saku and Y. Hirayama
      Physica E 22, 52 (2004).

    89. Effects of in-plane magnetic fields on spin transitions in bilayer quantum Hall states
      N. Kumada, K. Tagashira, K. Iwata, A. Sawada, Z. F. Ezawa, K. Muraki, T. Saku and Y. Hirayama
      Physica E 22, 36 (2004).

    90. Continuous transformation from spin- to pseudospin-type excitation
      A. Sawada, D. Terasawa, N. Kumada, M. Morino, K. Tagashira, Z. F. Ezawa, K. Muraki, T. Saku and Y. Hirayama
      Physica E 18, 118 (2003).

    91. Composite fermion interactions in bilayer nu=2/3 quantum Hall states
      N. Kumada, Y. Shimoda, M. Morino, A. Sawada, E. F. Ezawa, K. Muraki, T. Saku, and Y. Hirayama
      Proceedings of ICPS-26

    92. Phase diagram of interacting composite fermions in the bilayer nu=2/3 quantum Hall effect
      N. Kumada, D. Terasawa, Y. Shimoda, H. Azuhata, A. Sawada, E. F. Ezawa, K. Muraki, T. Saku and Y. Hirayama
      Phys. Rev. Lett. 89, 116802 (2002).
      >>abstract

    93. Integer and fractional quantum Hall effects in bilayer electron systems
      Z. F. Ezawa, A. Sawada and N. Kumada
      J. Phys. Chem. Solid 63, 1298 (2002).

    94. Various phase transitions in nu=2/3 bilayer quantum Hall states
      N. Kumada, D. Terasawa, Y. Shimoda, H. Azuhata, A. Sawada, E. F. Ezawa, K. Muraki, T. Saku and Y. Hirayama
      Physica E 12, 32 (2002).

    95. Preferred number of flipped spins in Skyrmion excitation
      N. Kumada, A. Sawada, E. F. Ezawa, H. Azuhata, S. Nagahama, K. Muraki, T. Saku and Y. Hirayama
      Physica B 298, 169 (2001).

    96. Skyrmion excitations in monolayer nu=1 and bilayer nu=2 quantum Hall states
      N. Kumada, A. Sawada, E. F. Ezawa, S. Nagahama, H. Azuhata, and T. Saku
      Proceedings of ICPS-25

    97. Doubly enhanced skyrmions in nu=2 bilayer quantum Hall states
      N. Kumada, A. Sawada, E. F. Ezawa, H. Azuhata, S. Nagahama, K. Muraki, T. Saku and Y. Hirayama
      J. Phys. Soc. Jpn. 69, 3178 (2000).
      >>abstract

    98. n(+)-GaAs back-gated double-quantum-well structures with full density control
      K. Muraki, N. Kumada T. Saku and Y. Hirayama
      Jpn. J. Appl. Phys. 39, 2444 (2000).

    99. Bilayer nu=2 quantum Hall state in parallel high magnetic field
      A. Sawada, E. F. Ezawa, H. Ohno, Y. Horikoshi, N. Kumada, Y. Ohno, S. Kishimoto, F. Matsukura and S. Nagahama
      Physica E 6, 615 (2000).

    100. Interlayer charge transfer in bilayer quantum Hall states at various filling factors
      K. Muraki, T. Saku, Y. Hirayama, N. Kumada, A. Sawada and Z. F. Ezawa
      Solid State Commun. 112, 625 (1999).

    101. Interlayer coherence in nu=1 and nu=2 bilayer quantum Hall states
      A. Sawada, E. F. Ezawa, H. Ohno, Y. Horikoshi, A. Urayama, Y. Ohno, S. Kishimoto, F. Matsukura and N. Kumada
      Phys. Rev. B 59, 14888 (1999).