Transport, heat, and anharmonic interactions

11 March 2010 (Thu) 15:45 - 16:30

4F seminar room (#431-2), MANA Bldg. Namiki site / 並木地区MANA棟4Fセミナー室

Prof. Nicola Marzari

Director of Materials Modeling Laboratory, Department of Materials, University of Oxford

Transport, heat, and anharmonic interactions

Vibrational excitations in solids are key to understanding electronic and thermal transport in bulk or nanostructured materials, and are probed directly by Raman, infrared, and neutron scattering. They can also be calculated directly from first-principles by applying perturbation theory to the electronic ground state; density-functional perturbation theory (DFPT) provides results of great accuracy for a very broad class of materials. We use DFPT to calculate phonon spectra and electron-phonon and phonon-phonon interactions, and to characterize the structure and the electronic and thermal transport of complex materials and nanostructures, where low-dimensionality can impose thermalization bottlenecks that are key hurdles to overcome in the current miniaturization trend. Examples will cover 1) the thermomechanical properties of bulk and low-dimensionality materials 2) finite-temperature Raman characterization of free-standing and strained graphene; 3) breakdown of ballistic transport in carbon nanotube interconnects; and 4) thermal conductivity in Si-Ge alloys and superlattices.

Dr. Yoshitaka Tateyama(館山佳尚)