Science at the Edge
Friday September 14, 2012
11:30 BPS 1400
Interdisciplinary Physics
Catching Electrons with Light
Paul Corkum
JASLAB, University of Ottawa
National Research Council of Canada Life Sciences Institute
Paul. [log in to unmask]
Abstract
Many scientists would say that it is intrinsically impossible to image a molecular orbital. A typical comment might be "Orbitals are but a mathematical construct -- a convenience for designing chemical reactions." This lecture will show that orbitals (specifically Dyson orbitals) are measurable.
We exploit an intense light pulse for this purpose. In intense infrared light, an electron tunnels from a molecule. After tunneling, the electron wave packet moves under the force of the light's electric field. The electron is first carried away from the molecule by the light wave and then driven back to it, where it interferes with the unionized portion of the orbital from which it just separated. This electron interference creates attosecond XUV pulses - the shortest pulses ever generated. The generated XUV radiation also contains all the information needed to determine the amplitude and relative phase of the orbital.
The lecture will conclude by describing how we might "film" orbital changes during a photochemical reaction - an upcoming molecular movie.
[Description: nature_2010b]
http://jaslab.ca/corkum_e.html
To meet with the speaker on Sept. 13th or 14th please contact R. Ghosh ([log in to unmask])
Shawna Prater / Secretary
Astrophysics Group
Michigan State University
567 Wilson Road, Room 3261
Biomedical Physical Sciences Bldg
East Lansing, MI 48824-2320
Ph: (517) 884-5601 Fax (517) 432-8802
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