Regensburg 2016 – scientific programme
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O: Fachverband Oberflächenphysik
O 18: Metallic Nanowires on Semiconductor Surfaces
O 18.1: Poster
Monday, March 7, 2016, 17:00–19:30, Poster A
Stepped Silicon Surfaces: Exploring the Formation of Spin Chains — Julian Aulbach1, •Tim Wagner1, Steven C. Erwin2, Ralph Claessen1, and Joerg Schaefer1 — 1Physikalisches Institut and Röntgen Center for Complex Materials Systems (RCCM), Universität Würzburg, Germany — 2Naval Research Laboratory, Washington DC, USA
Adsorption of a submonolayer of gold on various stepped Si(hhk) substrates yield the formation of atomic wire arrays with rather perfect structural order. As a specific representative, stabilization of the Si(553) surface by Au adsorption results in two different atomically defined chain types, one made of Au atoms and one of Si. The latter, situated at the step edges, forms a honeycomb nanoribbon which is subject to antiferromagnetic spin ordering [1, 2]. However, the extent to which the magnetic pattern can be modified, or suppressed, has remained unexplored. Here our approach is to exploit the tunability offered by the Si(hhk)-Au family, which exhibits not only varied terrace widths but also different bonding networks. Based on scanning tunneling microscopy and density-functional theory we reveal why magnetic patterns form on particular Si(hhk) surfaces but not on others, and propose broad strategies for using surface chemistry to control the formation or suppression of spin chains more generally.
[1] J. Aulbach et al., Phys. Rev. Lett. 111, 137203 (2013).
[2] S. C. Erwin and F. J. Himpsel, Nat. Commun. 1, 58 (2010).