Physical Society Colloquium
Interview for Faculty Position
Electron Dynamics in Complex Environments:
Frequency
Domain Experiments at Surfaces and Time Domain Experiments in Liquids
Pat Kambhampati
Department of Chemistry and Biochemistry
University of
Texas at Austin
The chemical mechanism of surface enhanced Raman scattering (SERS) is used as
a probe of adsorbate/substrate charge-transfer excitations on atomically
smooth, single crystal copper surfaces in ultra-high vacuum. It is
demonstrated that SERS and charge-transfer excitations are supported on
atomically smooth surfaces in contradiction to earlier consensus. It is found
that these excitations are sensitive probes of local electronic structure at
metal surfaces. The spatial extent, transition moment, and excited state
potential energy surfaces of these excitations are probed using SERS, EELS
and molecular spectroscopy simulations.
Experimental information on the spatial extent of the putative p and
conduction band states of the hydrated electron has been obtained by
monitoring and controlling the spatial separation of a photogenerated
electron/hole pair using a femtosecond laser pulse sequence. The experiments
employ femtosecond pulse sequences that allow for controllable preparation of
the various optically excited and precursor states of the equilibrated
hydrated electron. The results strongly confirm theoretical predictions on
the size and location of excited states of the hydrated electron. We further
investigate the time scale for hydrated electron solvation as a function of
the initial configuration of the electron/water system.
Thursday, March 13th 2003, 16:00
Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103)
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