Abstract: Plasmon, a collective type of electronic excitations generally featured by metallic systems, has been an old topic in physics. However, the prominent outlook of plasmonics for various applications in nanotechnology has stimulated its intense studies in recent years. Previous theoretical and experimental investigations on plasmons in metal nanostructures have mainly been focused on the Mie surface plasmons, as opposed to volume plasmons which cannot be optically excited in bulk metals. However, volume plasmons in small metal nanoclusters have been theoretically and experimentally shown to be non-negligible. Furthermore, in nanoscale size regime, quantum plasmons can have distinct behaviors that are different from classical plasmons. In this talk, I will report our recent quantum mechanical calculations of plasmon excitations in quantum-sized neutral Na clusters and also graphene. Our theoretical calculations are based on linear-response time-dependent density functional theory. In particular, the optical absorption spectrum, density response function and static polarizability of the Na clusters are evaluated. The low-energy plasmon dispersions in graphene are calculated and compared with electron energy loss spectroscopy.

 

About the Speaker: Professor Guang-Yu Guo is now Distinguished Professor at NTU's Department of Physics. He earned his doctorate in Physics from Cambridge University in 1987. From August of 2009 he was on secondment to National Chengchi University as a Chair Professor and Director of the Institute of Applied Physics. Professor Guo has won the Outstanding Research Award from the National Science Council three times in a row, and his areas of specialization are solid state physics, first principle computational materials science, and plasmonic metamaterials. Professor Guo has published copiously in solid state physics and advanced materials, and his scholastic attainments are widely recognized internationally. In 2005, Professor Guo became an APS (American Physical Society) Fellow owing to his academic contributions to computational solid state physics. In 2008, he was appointed as a Member of the Computational Physics committee of the International Union of Pure and Applied Physics (IUPAP). In 2013, Professor Guo received the honor of being named a Fellow of The Institute of Physics (UK). 

 

Date&Time: September 16, 2013 (Monday), 16:00 - 17:00
Location: 606 Conference Room