Faculty
Katsunori Wakabayashi
Major research activity
Theoretical Nanoscience, Condensed Matter Theory, Computational Physics
Our research target is to theoretically reveal the peculiar electronic, magnetic, transport and optical properties in nanoscale materials and atomically thin films such as graphene, transition metal dichalcogenides and other related two-dimensional materials using theoretical and/or computation method. Their electronic properties show the strong thickness dependence, i.e. number of layers. For example, the electronic states of graphene are described by the massless Dirac Fermion in sharp contrast with the conventional two-dimensional electron gas on the semiconductor devices. However, multi-layer graphenes possess ordinal non-Dirac electronic properties.
In further, the miniaturization of the electronic devices composed of graphene or/and atomically thin films inevitably demands the clarification of nanoscale edge effects on the electronic structures, electronic transport and magnetic properties of those systems. We have already shown that the presence of edges in graphene has strong implications for the low-energy spectrum of the π-electrons. It was shown that ribbons with zigzag edges possess localized edge states with energies close to the Fermi level resulting in the spin polarization near the edge.
On the background mentioned above, we are trying to clarify the peculiar features in electronic, magnetic and transport properties of nano- and meso-scopic systems based on carbon materials and atomically thin materials. In addition, we aim to design and explore theoretically the new functionalities as the next-generation devices based on their peculiar electronic properties.
Major relevant publications
- K. Wakabayashi, et.al. Electronic transport properties of graphene nanoribbons, New Journal of Physics, vol.11, 095016 (2009). doi: 10.1088/1367-2630/11/9/095016
- K. Wakabayashi, et.al., Electronic states of graphene nanoribbons with analytic solutions, Sci. Technol. Adv. Mater. vol. 11, 054504 (2010). doi: 10.1088/1468-6996/11/5/054504
- K. Wakabayashi, Chapter four: Electronic properties of nanographene, Physics and Chemistry of Graphene: Graphene to Nanographene, Pan Stanford Publishing, 2012, ISBN-13: 978-9814241489
- Hai-Yao Deng, and Katsunori Wakabayashi, Decomposition into Propagating and Evanescent Modes of Graphene Ribbons, Phys. Rev. B90, 045402 (2014). doi: 10.1103/PhysRevB.90.045402
- Sudipta Dutta, Katsunori Wakabayashi, Momentum shift of Dirac cone in silicene intercalated compound CaSi2 Phys. Rev. B 91, 201410(R) (2015). doi: 10.1103/PhysRevB.91.201410