Dresden 2014 – scientific programme

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O: Fachverband Oberflächenphysik

O 5: Topological Insulators: Mostly Structure and Electronic Structure (HL jointly with MA, O, TT)

O 5.7: Talk

Monday, March 31, 2014, 11:15–11:30, POT 051

Optoelectronic flow trajectories in topological insulators — •Paul Seifert¹, Christoph Kastl¹, Tong Guan², Kehui Wu², X. Y. He², Yongqing Li², and Alexander W. Holleitner¹ — ¹Walter Schottky Institut and Physik-Department, Technische Universität München — ²Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

We report on the optoelectronic properties of thin films of the topological insulator (Bi_xSb_1−x)₂Te₃ grown by molecular beam epitaxy. In spatially resolved experiments, we observe photocurrent patterns with positive and negative amplitude [1]. We interpret the patterns to originate from a local photocurrent generation due to potential fluctuations [1]. Exploiting the local photocurrent generation in combination with a sub 100-nm lithography, we visualize the current flow in nanoscale circuits based on topological insulators [2].

[1] C. Kastl, T. Guan, X. Y. He, K. H. Wu, Y. Q. Li, and A. W. Holleitner, Appl. Phys. Lett. 101, 251110 (2012). [2] C. Kastl et al., (2014).

We gratefully acknowledge financial support from the DFG-project HO3324/8 within the SPP 1666 on topological insulators.