Semiconductor nanocrystals and metal nanoparticles are key building blocks for nanophotonics, because they both interact strongly with light in a way that can be tuned by changing the size, shape, and composition of the particles. Light incident on noble-metal nanoparticles excites surface-plasmon resonances, or collective oscillations of conduction electrons, and light incident on semiconductor nanocrystals interactions with excitons, or bound electron-hole pairs. Time-resolved optical measurements on these particles can thus be used to probe electronic, chemical, and mechanical processes on ultrafast time scales and nanometer length scales. I will discuss some examples of the nanoscale physics that can be studied in this way: (1) measurements of charge relaxation, separation, and localization in semiconductor nanoparticles; (2) studies of nanoscale mechanical energy dissipation using plasmons as an optical probe; and (3) new optical properties that emerge from coherent interactions between plasmons in metal nanoparticles and excitons in semiconductor nanoparticles.

Location: Physics Bldg., Room 401