Setsunan University > Faculty of Science and Engineering >
Institute for Fundamental Sciences

Division of Physics

Osamu Kamishima [Professor]

Portrait Prof. Kamishima
When we put a ball at the bottom of a valley, the ball continues to stay there. This stable condition is called a "ground state". When we put a ball at the top of a mountain, the ball does not fall in keeping the environment quiet. This unstable condition is called an "excited state". But when we make a background noise around it, the ball falls down right away on the top of a mountain. Observing the way the "ball" put in an excited state falls down detects how noisy (disordered) the environment around the ball is. This disorder is the very source of familiar phenomena, such as "resistance" of electric currents and the "friction" essential for vehicles to climb the slope. My interest is to study the effect of the disorder on the fast ionic diffusion in the solid-state materials. This leads to the development of next-generation fuel cells or Li-ion batteries.

Takeshi Nagashima [Professor]

Portrait Prof. Nagashima
I am interested in the methods using terahertz time-domain spectroscopy, to study the dynamics of matters induced by optical or electromagnetic wave pulses. Light (electromagnetic wave) and electrons interact with each other in various ways. The detection of the reaction of electrons with light (electromagnetic wave) elucidates the behaviors of electrons in matters as electric charges. Especially, the free carriers react to terahertz waves of 10THz. Terahertz spectroscopy thus enables us to study the properties of semiconductors, such as the free carriers' density or mobility without destroying or touching them. I develop various terahertz spectroscopic methods, such as terahertz ellipsometry, suitable for evaluating the materials or devices. Electrons have a spin, as well. The interaction between the photons with electrons' spins is not large in general. But providing a huge amount of photons coherently using intense optical and electromagnetic wave pulses enables us to control electrons' spins and detect them optically. I have so far worked on the emission of terahertz wave from magnons excited by light pulses. In this way, we can expect that light or electromagnetic pulses will lead to novel physical phenomena or properties of materials.

Atsushi Higashiya [Professor]

Portrait Prof. Higashiya
Physical properties of materials are mainly determined by the electronic states in the vicinity of Fermi level. Therefore, to reveal the electronic states of the valence band is thought to be important for not only fundamental physics but also industrial application. I have been studying the bulk electronic states of the strongly correlated electron system, mainly 3d and 4f electron systems, by means of photoelectron spectroscopy measurement with synchrotron radiation light ranging from soft x-ray to hard one. In addition, I perform linear dichroism hard x-ray photoelectron spectroscopy by switching the polarization of the x-ray beam with two diamond phase retarders at BL19LXU of SPring-8 in collaboration with Prof. Sekiyama (Osaka University), recently. This method can clear the space distribution of electronic charge and determine their wave functions under crystal field, consequently.
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