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O: Fachverband Oberflächenphysik

O 5: Nanostructures at surfaces: Wires, tubes

O 5.3: Vortrag

Montag, 23. März 2009, 11:45–12:00, SCH A215

Self-Organized Atomic Gold Nanowires on Ge(001) Revealed by Scanning Tunneling Microscopy — •Christian Blumenstein, Sebastian Meyer, Jörg Schäfer, and Ralph Claessen — Physikal. Institut, Universität Würzburg, 97074 Würzburg

Atomic nanowires have become objects of intense research, as they host a wealth of physical phenomena not encountered in three-dimensional solids. They are synthesized by self-organization of metal adatoms on suitable semiconducting substrates that guide chain formation. Thus far, examples for quasi one-dimensional (1D) systems have been found where the Fermi surface hosts a charge density wave (CDW). This can be observed below room temperature in systems on Si(111) or high-index variants thereof. However, the ease of CDW condensation points at still significant coupling to the second dimension. In the search for better defined 1D systems, we have identified self-organized Au-induced chains on Ge(001) which grow in a long-range c(8× 2) phase and exhibit metallic behavior. In using scanning tunneling microscopy, we find that the wires are spaced by several Ge lattice constants, while their electron density is strictly confined laterally [1]. In turn, the metallic charge cloud is spread out very evenly in chain direction, as seen for a large range of bias values. Such exceptional degree of confinement may open a pathway to study non-Fermi liquid physics. The talk will review the various structural ingredients of this exceptional 1D electron system.

[1] J. Schäfer et al., Phys. Rev. Lett. 101, in press (Dec. 2008).