Date: Wednesday, February 28
Time: 12pm
Location: EN 3076
Speaker: Henry Wladkowski, Department of Physics and Astronomy
Title of Talk: Ultrafast Spectroscopy of Excitons in Low-Dimensional Metallic Systems
Excitons are well known quasi-particles in semiconductors, but are only observed in metals under quantum confinement. Due to their rarity, the internal energy structure, which is predicted to be hydrogenic in character, of excitons in metals is not yet fully explored. Within metallic single-wall carbon nanotubes, which are metals under 1D quantum confinement, excitons are known to dominate optical processes and have predicted internal energy transitions on the order of meV. These energies correspond to a region of the electromagnetic spectrum known as terahertz, a traditionally difficult part of the spectrum to generate and detect with no previous spectroscopy equipment available at the University of Wyoming. With that motivation to establish a terahertz spectroscopy system we set out to make it a reality diagnostic and preliminary scientific measurements of many samples. From there we have plans to expand the system's capabilities in order to probe the internal energy structure of metallic excitons.