Dresden 2014 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 45: Poster IV: One-Dimensional Metals: Reality or Fiction

DS 45.26: Poster

Donnerstag, 3. April 2014, 16:00–19:00, P1

Vibrational properties of Au/Si(553) nanowires — •Sergej Neufeld, Simone Sanna, and Wolf Gero Schmidt — Lehrstuhl für Theoretische Physik, Universität Paderborn, 33098 Paderborn, Germany

Metallic nanowires on semiconducting substrates such as silicon and germanium have been attracting considerable interest in the last decade. Besides various potential applications as non ohmic conductors, they are candidate systems for the demonstration of the basic concepts of one-dimensional physics such as electron correlation and Luttinger liquid behavior. Furthermore the phase transitions observed on these systems have been controversially discussed and are still poorly understood. Self organizing gold chains at vicinal surfaces such as the Si(553) and Si(557) are of particular interest, as the use of stepped templates allows to vary the geometric parameters and, thus, tune the inter-chain coupling. While well-established microscopic structural models of the Au/Si(553) and Au/Si(557) systems based on density functional theory are available in the literature, few is known about their vibrational properties. In this work, the phonon eigenmodes and eigenfrequencies of the Au/Si(553) wires are calculated from first-principles at the center of the Brillouin zone. Several surface localized phonon modes are found, whose phonon frequencies can be directly compared with the spectra obtained by Raman measurements.