AVS 46th International Symposium
    Surface Science Division Wednesday Sessions
       Session SS3+EM-WeM

Paper SS3+EM-WeM10
Spin-Orbit-Split Surface States in Clean and Alkali-Metal-Covered W(110)@footnote 1@

Wednesday, October 27, 1999, 11:20 am, Room 604

Session: Surface Electronic Structure
Presenter: E. Rotenberg, Lawrence Berkeley National Laboratory
Authors: E. Rotenberg, Lawrence Berkeley National Laboratory
J.W. Chung, Pohang Institute of Science and Technology, Korea
S.D. Kevan, University of Oregon
Correspondent: Click to Email
The broken symmetry at surfaces can give rise to a non-zero spin-orbit splitting of valence bands, as has recently been observed for the s-p derived surface state on Au(111).@footnote 2@ We now observe such a splitting of the d-derived surface state on W(110) and to a lesser extent, on Mo(110), and follow the evolution of the splitting as monovalent atoms are adsorbed. We find a dramatic increase in the splitting as a function of deposition for H and all alkali metals for coverages up to 1 ML. For Li, which shows the strongest change in splitting, we find a decrease in the splitting at the highest coverages near 1 ML. Our findings show that the spin-orbit splitting is a sensitive probe of the local surface conditions, to the extent that they are sampled by the surface state's wavefunction. The observed evolution is also directly relevant to recent observations of altered orbital magnetic structure vs. adsorbate coverage in magnetic materials. We propose a spin ordering for the associated Fermi contours which has important implications for spin excitations at surfaces. @FootnoteText@ @footnote 1@E. Rotenberg, J. W. Chung, and S. D. Kevan, Phys. Rev. Lett. 82 4066 (1999). @footnote 2@S. LaShell, B. A. McDougall, and E. Jensen, Phys. Rev. Lett., 3419 (1996).