Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 54: Electronic structure II
O 54.2: Vortrag
Mittwoch, 24. März 2010, 15:15–15:30, H33
One-dimensional Electron System of Au/Ge(001) Revealed by Angle-resolved Photoemission — •Sebastian Meyer1, Jörg Schäfer1, Christian Blumenstein1, Aaron Bostwick2, Eli Rotenberg2, and Ralph Claessen1 — 1Experimentelle Physik 4, Universität Würzburg, 97074 Würzburg, Germany — 2Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley 94720, California, USA
Self-organized atomic nanowires of noble metals on semiconductor surfaces are characterized by strict spatial separation and a high degree of charge confinement [1]. The ultimate width of single-atom dimension seems to be reached with gold chains on Ge(001).Thus they might offer the possibility to observe exotic properties, like a charge density wave (CDW), or, alternatively, a Luttinger liquid phase. Insight is gained by angle-resolved photoelectron spectroscopy (ARPES). We find that two shallow electron pockets disperse along the wire direction within the surface Brillouin zone, while a dispersion perpendicular to the wires is absent. This is confirmed by mapping the full Fermi surface (FS) topology, where sheets are found to be perfectly 1D without any interchain coupling. This is indicative of the virtual absence of coupling to the second dimension. Interestingly, while various nesting conditions are offered from the FS topology, no band back-folding from a CDW superstructure or energy gap opening is found, which opens a pathway for non-Fermi liquid physics. Thus the system emerges as a prototypical 1D electron system.
[1] J. Schäfer et al., Phys. Rev. Lett. 101, 236802 (2008).