IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Wednesday Sessions
       Session SS1-WeA

Paper SS1-WeA6
Focused Inelasticity in Scanning Tunneling Spectroscopy

Wednesday, October 31, 2001, 3:40 pm, Room 120

Session: New Opportunities in Surface Microscopy
Presenter: J.W. Gadzuk, National Institute of Standards and Technology
Authors: J.W. Gadzuk, National Institute of Standards and Technology
M. Plihal, KLA-Tencor
Correspondent: Click to Email

Scanning tunneling microscopy/spectroscopy of magnetic atoms adsorbed upon non-magnetic metal surfaces (possibly Kondo systems) has provided intriguing visual images and spectroscopic signatures in the form of Fano lineshapes in which the asymmetry depends in a diagnostically-useful way on tip location with respect to the adsorbate. Additional STM studies have demonstrated the ability of suitable two-dimensional nanostructures (such as "quantum corrals") to influence the surface electron transport that is part of the total elastic STM process. In a well known paradigm, an elliptical arrangement of Co atoms on Cu(111) gives rise to an apparent enhanced electronic communication between points on the surface which are near the two elliptical foci, showing some behavior consistent with classical ray tracing. The spectroscopic signature of a Kondo atom adsorbed at one focus shows an identical signature (though diminished in intensity) when the STM tip is placed over the vacant focus, suggestive of a mirage or "phantom atom". We report here on similar remote sensing for STM procedures involving inelastic tunneling in which adsorbate-surface or intra-molecular vibrational excitation occurs. We have extended our nonequilibrium theory of scanning tunneling spectroscopy@footnote1@ to include the additional processes, inelastic adsorbate vibrational excitation and elastic surface nanostructure scattering/focusing and the general theory has been applied to an elliptic corral realization. The characteristics of such "focused inelasticity" will be presented within the context of both Kondo systems such as Co/Cu(111) and also simple molecular systems. @FootnoteText@ @footnote 1@ M. Plihal and J. W. Gadzuk, Phys.Rev.B63(2001)085404.