Dresden 2014 – scientific programme

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MA: Fachverband Magnetismus

MA 55: Poster II

MA 55.110: Poster

Friday, April 4, 2014, 10:30–13:30, P2

THz spectroscopy on the topological insulator Bi2Te3 — •Nick Borgwardt¹, Gregor Mussler², Malte Langenbach¹, Joachim Hemberger¹, and Markus Grüninger¹ — ¹II. Physikalisches Institut, Universität zu Köln, Cologne, Germany — ²Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, Germany

Topological insulators are one of the most discussed areas of current research in condensed matter physics. Bi₂Te₃ is a 3D topological insulator with the advantage of a relatively large band gap (∼0.2 eV) and a reduced bulk conductivity. Thin films of Bi₂Te₃ with thicknesses between 9nm and 30nm were grown on high-resistance Si (111) wafers using MBE. By means of cw-THz spectroscopy based on photomixing in combination with far-infrared Fourier spectroscopy, we studied the transmission in the frequency range from 3 cm⁻¹ to 700 cm⁻¹ as a function of temperature. The goal is to distinguish between surface conductance and bulk conductivity.