Events at Physics |
Events on Thursday, February 5th, 2009
- R. G. Herb Condensed Matter Seminar
- Probing Electron Energy Distribution in Carbon Nanotubes
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Yung-Fu Chen, Frederick Seitz Materials Research Lab, UIUC
- Abstract: Carbon nanotubes are considered model one-dimensional systems, and their electronic transport is strongly affected by electron-electron (e-e) interactions. Measurements of the non-equilibrium electron energy distribution function in nanotubes may directly determine electron energy relaxation rates, which may also tell us e-e scattering rates and therefore something about e-e interactions in nanotubes. We developed techniques to perform tunneling spectroscopy on nanotubes using non-invasive superconducting probes, which allows us to measure the shape of the electron energy distribution locally in nanotubes that have bias voltages applied between their ends to drive the electrons out of equilibrium. We find that at low temperatures electrons in nanotubes maintain their energy distribution across a few microns channel length. Surprisingly, the energy relaxation rate sometimes grows substantially when the temperature is raised to only 1.5 K.
- Host: Robert McDermott
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Cosmology and the LHC
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Carlos E M Wagner, Argonne National Laboratory & University of Chicago
- Abstract: The LHC is expected to shed light on the physics behind the mechanism of electroweak symmetry breaking, associated with the generation of mass of all known elementary particles. There are good reasons to think that the same physics is responsible for the origin of dark matter and, perhaps, of the observable matter-antimatter asymmetry. In this talk I will summarize the arguments that support the above statements and provide a few examples of the interplay between cosmology and collider physics at the LHC.
- Host: M J Ramsey-Musolf
- Special Plasma Seminar
- "Ion Current Estimations in the Irvine Field Reversed Configuration:
- Time: 4:00 pm - 5:15 pm
- Place: 5280 Chamberlin Hall
- Speaker: Wayne Harris, University of California/Irvine