Author: Chris S Reilly
Requested Type: Poster
Submitted: 2015-04-20 11:41:27
Co-authors: Robert Stevens IV, Greg Sitz
University of Texas at Austin
3406 Cedar St.
Austin, TX 78705
Hydrogen molecules incident on a Si(100) surface are pumped to an excited rotational state using stimulated Raman scattering. The distribution of rotational angular momenta of pumped molecules is peaked about the direction of pump polarization. Detection of scattered molecules is accomplished using resonantly-enhanced multi-photon ionization ((2+1) REMPI). Modulation depth of REMPI signal with probe polarization gives measure of survival of rotational alignment. Comparison is made between alignment survival of molecules oriented perpendicular and parallel to the surface normal.
Our work uses molecules instead of light to probe surface structure. The surface can couple energy between different molecular degrees of freedom or itself exchange energy with the molecule.