Atomic chain ordering with ultra-long periods

Pb/Si(5 5 7)

verfasst von: Marcin Czubanowski, Herbert Pfnür, Christoph Tegenkamp
Abstract: As shown previously, Pb on vicinal Si(5 5 7) refacets the surface into a (2 2 3) facet orientation at a Pb coverage of 1.31 ML. This facet formation is electronically stabilized by Fermi nesting and leads to one-dimensional conductance. Electronic correlation seems to be responsible also for the periodic arrangement of atomic Pb chains which decorate the step edges at concentrations exceeding 1.31 ML, up to a concentration of 1.5 ML. Instead of random step decoration, periodicities up to six (2 2 3)-terrace widths (28 lattice constants, 93 Å) have been found. These depend inversely on excess Pb concentration and end at a concentration of 1.52 ML when all steps are decorated with a line density equal to the Si density at steps. These one-dimensional periodicities can be explained assuming that split-off states from surface bands are completely filled by two electrons per Pb atom with corresponding gap opening. This behavior is reminiscent of the formation of charge density waves with tunable wavelengths as a function of excess Pb concentration, and indicates strong electron correlation in this strongly anisotropic 2d system. The alternative, simple band filling within a rigid band model is expected to destabilize the (2 2 3) facet structure upon further adsorption of Pb, which has not been observed.
Organisationseinheit(en): Institut für Festkörperphysik
Typ: Artikel
Journal: Surface Science
Band: 603
Seiten: L121-L124
ISSN: 0039-6028
Publikationsdatum: 18.08.2009
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Physik der kondensierten Materie, Oberflächen und Grenzflächen, Oberflächen, Beschichtungen und Folien, Werkstoffchemie
Elektronische Version(en): https://doi.org/10.1016/j.susc.2009.08.013 (Zugang: Unbekannt)

BibTeX

@article{94cbcda724f644aea45bd3560bdff1a6,
title = "Atomic chain ordering with ultra-long periods: Pb/Si(5 5 7)",
abstract = "As shown previously, Pb on vicinal Si(5 5 7) refacets the surface into a (2 2 3) facet orientation at a Pb coverage of 1.31 ML. This facet formation is electronically stabilized by Fermi nesting and leads to one-dimensional conductance. Electronic correlation seems to be responsible also for the periodic arrangement of atomic Pb chains which decorate the step edges at concentrations exceeding 1.31 ML, up to a concentration of 1.5 ML. Instead of random step decoration, periodicities up to six (2 2 3)-terrace widths (28 lattice constants, 93 {\AA}) have been found. These depend inversely on excess Pb concentration and end at a concentration of 1.52 ML when all steps are decorated with a line density equal to the Si density at steps. These one-dimensional periodicities can be explained assuming that split-off states from surface bands are completely filled by two electrons per Pb atom with corresponding gap opening. This behavior is reminiscent of the formation of charge density waves with tunable wavelengths as a function of excess Pb concentration, and indicates strong electron correlation in this strongly anisotropic 2d system. The alternative, simple band filling within a rigid band model is expected to destabilize the (2 2 3) facet structure upon further adsorption of Pb, which has not been observed.",
keywords = "Atomic chains, Charge density waves, SPA-LEED, Superlattices",
author = "Marcin Czubanowski and Herbert Pfn{\"u}r and Christoph Tegenkamp",
note = "Funding information: We gratefully acknowledge the fruitful discussions with Tammo Block. The work is financially supported by the Deutsche Forschungsgemeinschaft .",
year = "2009",
month = aug,
day = "18",
doi = "10.1016/j.susc.2009.08.013",
language = "English",
volume = "603",
pages = "L121--L124",
journal = "Surface Science",
issn = "0039-6028",
publisher = "Elsevier",
number = "19",
}