Research Topics

Research Topics and Member

The Division of Nanocarbon Research covers topics of nanocarbons from fundamental to applied researches by collaboration of experts in theoretical and experimental condensed matter physics, electrical engineering, thermal engineering, and biophysics. We expect synergy effects by enhancing mutual discussion and exchange of ideas in the division. Our main topics are the following (1) Material Sciences in Nanospace (2) Nanotube-Biomolecule Interaction (3) Growth Control of Nanocarbons (4) Theoretical Study on Novel Properties

(1) Materials Science in Nanospace

・We use an individual single-walled carbon nanotube as a well-defined nanospace, and study the interactions between nanotubes and molecules such as water and alcohol by optical spectroscopy, electron microscopy and molecular dynamics simulations. Thereby, we elucidate the structure and phase of the molecules in the nanospace. We also study the interaction between nanotubes and polymers, aiming at application of polymer-nanotube composites.

・We regard systems composed of nanotubes with adsobates or defects as extended composites, and study the basic properties by first-principles electronic state calculations and model calculations.

Water molecules adsorbed on carbon nanotubes.

(a) SWNT suspended on silica pillar， (b) Photoluminescense spectra of SWNT in vacuum，(c) Photoluminescense spectra of SWNT in water vapor.

(2) Nanotube-Biomolecule Interaction

・We study structural properties of composites composed of nanotubes and biomolecules (DNA, protein). Specifically, we fabricate biodevices with nanotubes functionalized by DNA, and examine whether the structural properties of the biomolecules are retained, and whether the molecular recognition function is retained.

・We theoretically investigate the host-guest interactions of the nanotube/ biomolecule composites, and clarify the effect on the properties of the composites.

DNA-CNT thin-film.

DNA-CNT composite.

(3) Growth Control of Nanocarbons

・We develop techniques for precise structural control of nanocarbons based on the various nanotube synthesis techniques such as vertically-aligned growth on silicon and silica substrates and horizontally-aligned growth on quartz substarte.

・We study novel synthesis methods of nanocarbons utilizing arc discharge by changing the discharge ambience, electrode materials, etc. We also study novel methods for graphene synthesis.

Horizontally-aligned growth carbon nanotubes

(4) Theoretical Study on Novel Properties

・We perform first principles or semi-empirical simulations in order to clarify the responses of electrons or atoms in nanocarbons to laser or high electric field. We are aiming at theoretical descriptions of experimentally observed phenomena such as field electron emission, laser induced electron emission, laser stimulated coherent phonon generation/plasma oscillation excitation, etc.

・We analyze the electric transport in nanocarbons by using simulation techniques in order to understand the interactions between nanotube/graphene and high speed electrons.

・We theoretically study the super-conductivity of nanotube and graphene, and predict the basic properties.

・We analyze the electronic structure of nanotube composites in their ground states, and also the phenomena relating to their excited states.

Field electron emission from the top of SWNT.

Graphene field-effect-transistor.

Tribology in nanocarbon materials.