[HANAWA, Tomoyuki] Professor, D. Sc.
[MATSUMOTO, Ryoji] Professor, D. Sc.
[MIYAJI, Shigeki] Associate Professor, D. Sc.
Astrophysics is not a single and/or a simple field of physics but a complex of many fields of physics which applied to astophysical objects. With the wide variety of knowledge of physics such as elementally particle physics, nuclear physics, condensed matter physics, plasma physics, etc., Astrophysics figures out phenomena at far distant space. Astrophysics is also an experimental physics to develop various kind of detectors with improved sensitivity and spacial and wave length resolutions in order to observe Astrophysical objects. In our laboratory, both theoretical and observational approaches are pursued. Recent themes for graduate students are 3-Dimensional Magneto-Hydro Dynamics, Analysis of Solar X-ray Images of Transient Phenomena, Numerical Simulation of Proto-Star Collapse, etc. We are also interested in pursuing new simulation technics for massively parallel and parallel vector supercomputers.
[KIMURA, Tadahiko] Professor, D. Sc.
[KONDO, Keiichi] Associate Professor, D. Sc.
[YAMADA, Atsushi] Associate Professor, D. Sc.
Elementary Particle Physics is a field to study characteristics of fundamental particles and laws which govern these particles. Present themes of this laboratory are concentrated on its theoretical side as follows:
- Quantum Theory of Gauge Fields.
- Critical Phenomena of Quantum Field.
- Elementary Particle Models beyond the Standard Model.
- Quantum Theory for Condensed Matter Field. Recent subjects for senior study (seminar style) are quantum field theories, gravity, and general relativity.
[KAWAI, Hideyuki] Associate Professor, D. Sc.
[YOSHIDA, Shigeru] Associate Professor, D. Sc.
[MASE, Keiichi] Research Associate, D. Sc.
Why matter have mass? Why the Universe appears in the way they are? These ultimate questions have been among the biggest intellectual challenging for human being. To understand our world in such basic level requires to investigate characteristics of the elementary particles that are fundamental particles forming the matter in the Universe. These particles are generated by accelerators built by the human technology, or can be seen among the cosmic rays produced by ultra-high energy phenomena in astronomical objects. Our group is working on the research projects to bring new and deep understanding of the matter and our Universe, by studying properties of the elementary particles experimentally generated or observing ultra-high energy cosmic rays and neutrnos.
[ NATSUME, Yuhei] Professor, D. Sc.
The Laboratory is devoted to theoretical investigations of condensed matters and statistical physics. In particular, following subjects are now proceeding:
- Optical properties by magnetic excitations in quantum spin systems.
- Computational physics on phase interferences in quantum dynamics.
- Conduction phenomena in quantum dots including spins.
- Quantum chaos in magnetic compounds.
[KOHORI, Yoh] Professor, D. Eng.
[OHAMA, Tetsuo] Associate Professor, D. Sc.
[FUKAZAWA, Hideto] Research Associate, D. Sc.
In solid-state materials, various physical properties, which are for example electric conductivity, magnetic properties, etc., are governed by the electronic states of their constituing elements. For electrons in solid-state materials, room temperature is enough low temperature because their characteristic temperature of the electronic states is about a hundred higher than room temperature. This leads to the attracting physical phenomena such as magnetic order, superconductivity and so on which can be explained in terms of quantum physics.
To understand these kinds of electronic states is one of the impotant subjects of physics and is strongly related with wide varieties of application.
In our educational field, we apply magnetic resonance by using electromagnetic wave and photo scattering by using laser beam in order to understand electronic states in solid-state materials. We also utilize wide range of temperature between 0.05 K and 1000 K, high pressure up to about 10,000 atm and high magnetic field.
Main subjects of our field are as follows.
- Magnetic order and its related dynamical behavior
- Phase transition in crystalline lattice
- Unconventional superconductivity in rare-earth and uranium compounds
- Metal-insulator transition in conductive oxides
- Quantum magnetism in materials which have layered or ladder structure
[YAMADA, Isao] Professor, D. Sc.
Materials show various characteristics. For example, some show very high magnetism and the others do not, or some are electrical and thermal conductors and the others are insulators. Why these differences take place? The answer is based on the fact that most of physical characteristics of materials are determined by the states of electrons in each material. Electrons have spin, a kind of the smallest unit of magnets. When electro-magnetic waves hit the material, electro-magnetic waves of certain wave length may be absorbed or scattered because of the correlation between the magnetic field of electro-magnetic wave and the spin of electrons. On the other hand, the material may change its characteristics drastically depending on its temperature. At our laboratory, experiments to measure magnetical and/or electrical characteristics at from very low temperature (nearly absolute zero) to 1000 C by correlation with radio, micro, and optical laser waves.
[NAKAYAMA, Takashi] Professor, D. Sc.
Our nano-science laboratory is investigating the physics in the nano-scale world, which is the main science in 21th century and becomes the basis of nano-technology and nano-bio science. In this small world, several hundred atoms often condense as beautiful forms such as pyramids, spirals, soccer balls, reconstructed surfaces, and ordered hetero-interfaces. These systems become fundamental units in material hierarchy to produce complex systems such as DNA and promote efficient energy and information transfers. Moreover, these systems exhibit exotic physical properties; for example, they are harder than the diamond and promote current quite different from a conventional Ohm's law current. We are studying why such unique shapes appear and what are origins of such unique properties, based on quantum mechanics, many-body theories, and nonlinear non-equilibrium concepts.
The goal of our studies is to elucidate universal laws that control this fundamental world. By these studies, in the near future, one can freely design new materials and living things that have never existed in the nature. Basic education necessary for the nano-science research is provided through lectures, seminars, etc., and in the graduate school the worldwide top-level nano-science researches are carried out collaborating with overseas groups.
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Figure Caption: Computer simulation of electron injection from Si substrate into amino acid. This type of injection artificially controls protein functionals. |
[OGAWA, Kengo] Professor, D. Sc.
[IWASAKI, Saburo] Associate Professor, D. Sc.
[KURASAWA, Haruki] Professor, D. Sc.
[NAKADA, Hitoshi] Associate Professor, D. Sc.
Nuclear Physics is a basics in order to understand the matter, i.e., atoms. Atom itself contains many elementary particles in it and shows complicated characteristics when its atomic number is higher and its proton/neutron ratio is far from that of stable isotopes. Using numerical simulation, atomic models are evaluated and detailed structures inside atoms are determined. Our themes are as follows:
- Shell models for various kind of nuclei.
- Collective Modeling of Nuclei.
- Relativistic Nuclear Theory using Quantum Chromo Dynamics.
- Quantum Monte Carlo Method for nuclear structure.
[MURO, Kiyofumi] Professor, D. Eng.
[OTO, Kenichi] Associate Professor, D. Sc.
[MINO, Hirofumi] Research Associate, D. Sc.
Quasi-particles, electron and hole behave just like real particles in semiconductor and present a variety of phenomena. These behaviors have been utilized in the electronics devices which is the core of information technology. Development of recent material processing technology enabled the fabrication of nanometer scale structure in semiconductor, i.e., quantum well and quantum dot. Quasi-particles confined in such a meso-scopic structure behave in a different way and present prominent quantum effects.
We study quantum transport phenomena at low temperature and in a high magnetic field by fabricating specially designed pattern by e-beam lithography to understand the properties of strongly correlated electronic states. We also study the spin and carrier dynamics of meso-scopic system by femto-second time-resolved laser spectroscopy and high resolution Raman spectroscopy to try manipulate the spin in order to yield new quantum devices.
[OHTA, Yukinori] Associate Professor, D. Eng.
The scientific activity of our group is centered on the theoretical and computational studies of the anomalous properties of commonly named strongly-correlated electron systems. A broad range of interesting physical phenomena occur here, the studies of which have extended the physics beyond the domain of simple noninteracting theories or perturbative treatments. Examples are superconductivity of unconventional types, fluctuations and ordering of spin degrees of freedom, crystallization of charge carriers, and a variety of quantum magnetisms. These phenomena are observed in materials such as cuprates and other transition-metal oxides, molecular or organic crystals, and rare-earth systems.
Research in our group follows both analytical and computational approaches; a variety of quantum-field-theoretical methods are used for analytical approaches and a Lanczos diagonalization method, density-matrix renormalization group (DMRG) method, and quantum Monte Carlo (QMC) method are used for computational ones.
Our on-going research projects are the following:
- Theoretical and computational studies of strongly-correlated electron models such as Hubbard, t-J, and Anderson-lattice models.
- Mechanisms of unconventional superconductivity of low-dimensional molecular conductors and other correlated metals.
- Anomalous electronic properties and quantum phase transitions of strongly-correlated electron systems such as transition-metal oxides and organic materials.
- Mechanisms of cuprate high-temperature superconductivity.
- Dynamics of heavy-electron systems such as f-electron compounds and Kondo insulators.
- Development of numerical simulation techniques such as DMRG and QMC methods.
- Magnetisms and local structures of intermetallic compounds.