Research Activities

　　　　　　　　　　　　　　Members

　　　　　　　　　　　　　　Recent Publications

Research Activities

　　　 Interacting many-particle systems exibit many interesting phenomena such as
       magnatism and superconductivity.Our group focuses on the theoretical study 
       of those interacting many-particle systems.
　
       (1) Electron correlations are essentail in certain transition-metal,lanthanide,
       and actinide alloys. Effective masses of quasi-particles are 10-1000 times as
       large as electron mass. Such alloys are called heavy-electron systems. One of
       our projects is to clarify theoretically exotic magnetism and superconductivity
       in heavy-electron systems. It includes a theoretical study on the mechanism 
       of high-temperature superconductivity in cuprate oxides.
　
       (2) 3He particles, which obey Fermi statistics, undergoes a phase transition
       around 3mK into a couple of superfluid phases. The Cooper pairs of those
       phases have the internal degrees of freedom to display phenomena different
       from the conventional BCS superconductors. Some of the above-mentioned heavy
       electrons are also reported to form anisotropic Cooper pairs. Another project
       is to study those phenomina characteristic of the anisotropic Cooper pairs. 
　
 

Members

    Staff
　
    OHKAWA, Fusayoshi (Prof.)         fohkawa@phys.sci.hokudai.ac.jp     011-706-2694

    KITA, Takafumi (Associate Prof.)  kita@phys.sci.hokudai.ac.jp        011-706-2687
　
    Student
　
    MIYAI, Eiji (D3)                  miyai@phys.sci.hokudai.ac.jp       011-706-3219
　
    SATOH, Hiroyuki (D2)              hsatoh@phys.sci.hokudai.ac.jp      011-706-3219
    
    YASUI, Kouji (M2)                 yasui@phys.sci.hokudai.ac.jp       011-706-3219
　
    SHIMIZU, Hirofumi (M1)            shim@phys.sci.hokudai.ac.jp        011-706-3219
    
    NATSUME, Kazuyuki (M1)            natsume@phys.sci.hokudai.ac.jp     011-706-3219
　
    SUDA, Tomoya <Senior>             t-suda@phys.sci.hokudai.ac.jp                  

Recent Publications

 
    (1998)
    F. J. Ohkawa: Phys. Rev. B57 (1998) 412-425.
      Quantum and thermal spin fluctuations in itinerant-electron magnetism,

    F. J. Ohkawa: J. Phys. Soc. Jpn. 67 (1998) 525.
      Magnetic Exchange Interaction between Quasiparticles in Itinerant-electron 
      magnets.

    F. J. Ohkawa, K. Onoue and H. Satoh: J. Phys. Soc. Jpn. 67 (1998) 535.
      Sinusoidal and Helical Structires in Itinerant-electron magnets.

    H. Satoh and F. J. Ohkawa: Phys. Rev. B57 (1998) 5891-5899,
      Field-induced ferromagnetic exchange interaction in metamagnetic transitions 
      of heavy-electron liquids.

    F. J. Ohkawa: to be  published in Physica C301, issue 3 & 4, June 1998.
      Anisotropic renormalization of quasiparticles in cuprate-oxides superconductors.
      
    T. Kita: J. Phys. Soc. Jpn. 67 (1998) 216.
      Angular Momentum of Anisotropic Superfluids at Finite Temperatures.
      
    T. Kita: J. Phys. Soc. Jpn. 67 (1998) No.6.
      Solving the Ginzburg-Landau Equations with Magnetic Translation Group.

    T. Kita: J. Phys. Soc. Jpn. 67 (1998) No.6.
      A Microscopic Theory of Abrikosov Lattices. I. Basic Formalism.

    (1996)
    F. J. Ohkawa: to be published in Phys. Rev. B54 (1996) 15388.
      Heavy quasi-particles and Cooper-pair interaction in the Hubbard model
　
    T. Kita: J. Phys. Soc. Jpn. 65 (1996) 664.
      The Angular Momentum Paradox of 3He-A
　
    T. Kita: J. Phys. Soc. Jpn. 65 (1996) 908. 
      Real-Space Formalism of the Theory of Superconductivity
 
    T. Kita: J. Phys. Soc. Jpn. 65 (1996) 1355.
      Perturbation Expansion for a Fermi Superfluid. I
　
    T. Kita: J. Phys. Soc. Jpn. 65 (1996) 1373.
      Perturbation Expansion for a Fermi Superfluid. II
　
    (1995)
    N. Matsumoto and F. J. Ohkawa: Phys. Rev. B51 (1995) 4110.
      Kondo lattice model in infinite dimensions
　
    (1994)
　  F. J. Ohkawa and N. Matsumoto: J. Phys. Soc. Jpn. 63 (1994) 602. 
      On the Superexchange Interaction in the Hubbard Model