Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 37: Posters: Plasmonics, Electronic Structure and Spin-Orbit Interaction, Semiconductor and Insulator Surfaces, Nanostructures
O 37.55: Poster
Dienstag, 1. April 2014, 18:30–22:00, P2
Multi probe transport measurements on Bi2Se3 thin films — •Sebastian Bauer, Paul Graf, Rolf Möller, and Christian A. Bobisch — Faculty of Physics, Center for Nanointegration Duisburg-Essen, University of Duisburg-Essen, 47048 Duisburg, Germany
Since their prediction, topological insulators (TIs) like Bi2Se3 are very popular in condensed matter physics due to their peculiar electronic properties. At the surface of 3D TIs a conducting and spin polarized surface state evolves, which does not allow the direct backscattering of electrons [1]. We studied the transport field of a 4.5 QL thin Bi2Se3 film by scanning tunneling potentiometry, an extended scanning tunneling microscopy (STM) technique which allows us to analyze the microscopic topography and the correlated microscopic electrochemical potential of the surface simultaneously [2]. The Bi2Se3 film was prepared in-situ on a reconstructed Si(111)-(√3x√3)-Bi according to Zhang et al. [3]. On large scale measurements of the electrochemical potential we observe a lateral gradient of the electrochemical potential of the Bi2Se3 surface. Both, the microscopic sheet conductance and the macroscopic sheet conductance of the 4.5 QL film agree well to other data from literature [4]. A thermovoltage signal at surface step edges indicates the local variation of the density of states [5].
[1] M. Z. Hasan, C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010). [2] A. Bannani, C. A. Bobisch, R. Möller, Rev. Sci. Instrum. 79, 083704 (2008). [3] G. Zhang, et al., Appl. Phys. Lett. 95, 053114 (2009). [4] A. A. Taskin et al., Phys. Rev. Lett. 109, 066803 (2012). [5] T. Zhang et al., Phys. Rev. B. 87, 115410 (2013).