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DS: Fachverband Dünne Schichten
DS 18: 1D Metal Wires on Semiconductors I
(Joint session of DS and O, organized by O)
DS 18.5: Talk
Tuesday, March 8, 2016, 11:45–12:00, S052
Spin correlations in the Si(553)-Au nanowire system — •B. Hafke1, T. Frigge1, B. Krenzer1, J. Aulbach2, R. Claessen2, J. Schaeffer2, and M. Horn-von Hoegen1 — 1Universität Duisburg-Essen, Lotharstr. 1, 47057 Duisburg — 2Universität Würzburg, Physikalisches Institut and Röntgen Center for Complex Materials Systems (RCCM), 97074 Würzburg
To study the microscopic mechanism of formation, stabilization, and interaction in low dimensional systems we used Si(553) as vicinal surface to enforce the nucleation of Au into one dimensional wires. Deposition of 0.5 ML Au results in the formation of one pair of 1D Au atomic chains per Si terrace exhibiting a twofold periodicity. These metallic wires are structurally terminated by Si step edge atoms, which show a threefold periodicity of the Si atoms along the rows. Theory predicts an antiferromagnetic spin ordering of every third Si step edge atom [1]. The long-range interaction of the twofold and threefold periodicity is investigated by spot-profile analysis in SPA-LEED at a sample temperature of 80 K. The strict twofold periodicity of the Au atoms is not correlated between adjacent wires. In contrast the threefold ordering of the Si spins exhibit a clear short range order perpendicular to the Au wires. Both results support the structure model where the interrow correlation is mediated by the spin-spin interaction of adjacent Si step edge atoms.
[1] S. C. Erwin and F. J. Himpsel, Nature Commun. 1, 58 (2010).