Dresden 2014 – scientific programme

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DS: Fachverband Dünne Schichten

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

DS 45.17: Poster

Thursday, April 3, 2014, 16:00–19:00, P1

Transport in spatially restricted ensemble wire systems — Frederik Edler, •Stephanie Demuth, Herbert Pfnür, and Christoph Tegenkamp — Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannover, Germany

Low dimensional electron gas systems can be grown by self-organized growth of metals on appropriate semiconducting surfaces. In the recent past various atomic wire structures are found with special properties like Luttinger liquid behavior or Peierls-driven metal insulator phase transitions. Instabilities are directly accessible by surface transport measurements. In order to reveal a deeper insight into the role of coupling of the systems to their environment, transport in spatially restricted areas is highly desirable to correlate imperfections and/or finite size effects directly with transport findings. We have developed a fully in-situ process for Si(111) surfaces to perform such measurements by means of a 4-tip STM/SEM system. For this, oxidation of Si samples is necessary. The SEM e-beam is used to reduce locally the SiO₂ to SiO which is volatile at around 760 ^∘C resulting in Si-windows of arbitrary shape. The subsequent adsorption of 1 ML Ag at 550 ^∘C leads to Ag √3-reconstructions only within these windows. Feedback controlled Au-coated W-STM tips are navigated under SEM control for contacting the Ag reconstructions. Transport measurements reveal 2D conductivity of 1.4 kΩ in reasonable agreement with former studies and no contribution of remaining not percolated Ag clusters on SiO₂. We are extending this technique to the In/Si(111) system for a systematically study of finite size effects.