IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Thursday Sessions
       Session SS2-ThM

Paper SS2-ThM10
Theoretical Analysis of Field Emission from Atomically Sharp Al Tips

Thursday, November 1, 2001, 11:20 am, Room 122

Session: Electronic Structure II
Presenter: Y. Gohda, The University of Tokyo, and CREST, Japan Science and Technology Corp.
Authors: Y. Gohda, The University of Tokyo, and CREST, Japan Science and Technology Corp.
S. Watanabe, The University of Tokyo, and CREST, Japan Science and Technology Corp.
Correspondent: Click to Email
Well-conditioned tips, which end with a single atom, are of current interest, because they produce self-collimated, coherent electron beams, total energy distribution (TED) of which can have multiple peaks (MP).@footnote 1,2@ However, the origin of the MP in TED has been controversial and thus has not been understood well: Binh et al. claimed that they had observed MP from pure W(111) surface with single-atom protrusion,@footnote 1@ while Yu et al. claimed that carburization was essential in observing MP from metal-carbide protrusions.@footnote 2@ In the present work, field emission from Al(100) surface having single-atom protrusion without any impurity is analyzed employing the method newly developed by Gohda et al.,@footnote 3@ which is based on the self-consistent density functional theory including scattering states. We have found that MP in TED of field emission current becomes remarkable as the local potential barrier in front of the topmost Al atom dissapears with increase in applied field strength. We have also clarified that the peak below the Fermi energy is attributed to localized sates at the topmost Al atom, while the peak at the Fermi energy comes from delocalized states. @FootnoteText@ @footnote 1@ V. T. Binh et al., Phys. Rev. Lett. 69, 2527 (1992). @footnote 2@ M. L. Yu et al., Phys. Rev. Lett. 77, 1636 (1996). @footnote 3@ Y. Gohda et al., Phys. Rev. Lett. 85, 1750 (2000).