Regensburg 2016 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

DS: Fachverband Dünne Schichten

DS 24: 1D Metal Wires on Semiconductors II
(Joint session of DS and O, organized by O)

DS 24.1: Talk

Tuesday, March 8, 2016, 14:00–14:15, S052

Infrared Plasmonic Investigation of Band Filling-Induced Metal-to-Insulator Transition in Au Chains on Si(111)-5x2-Au — •Fabian Hötzel¹, Kaori Seino², Friedhelm Bechstedt², and Annemarie Pucci¹ — ¹Kirchhoff-Institut für Physik, Universität Heidelberg, Heidelberg, Deutschland — ²Institut für Festkörpertheorie und -optik, Universität Jena, Jena, Deutschland

The investigation of infrared plasmon polaritons on the Si(111)-5x2-Au surface underlines the metallic character of the system [1] and its Kwon-Kang atomic structure model [2] with seven Au atoms per 5x2 surface unit cell. However, upon evaporating an additional 0.1 monolayer Au amount, the system undergoes a metal-to-insulator transition [3] but the 5x2 symmetry remains unchanged as proven by reflection high energy electron diffraction. This phase transition was in situ observed by means of the infrared plasmonic signal attenuation with coverage. Band-structure calculations reveal that the transition is induced by band filling of the one-dimensional half-filled band at the Fermi energy. The insulating phase represents an indirect semiconductor with a band gap of 0.29 eV. Moreover, a new surface structure model with eight Au atoms per unit cell, including the additional Au atoms, is developed for the 5x2 symmetry. By annealing the system, the plasmonic signal is recovered which shows that the phase transition is reversible. This contribution is part of the DFG Research Unit FOR 1700.
Hötzel, F. et al. Nano Lett. 2015, 15, 4155-4160.
Kwon, S. G. et al. Phys. Rev. Lett. 2014, 113, 086101.
Hötzel, F. et al. J. Phys. Chem. Lett. 2015, 6, 3615-3620.