Regensburg 2013 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 12: Poster 1
DF 12.5: Poster
Dienstag, 12. März 2013, 10:30–13:30, Poster D
A scanning tunneling spectroscopy investigation of the Bi2Te3 surface — •Thomas Bathon, Paolo Sessi, Lydia El-Kareh, and Matthias Bode — Physikalisches Institut, Experimentelle Physik II, Universität Würzburg,
We present a combined scanning tunneling microscopy (STM) and spectroscopy (STS) characterization of the structural and electronic properties of the topological insulator Bi2Te3. By interpreting the bias-dependent topographical evolution of defects we can show that they make samples n-doped. With the help of Fourier-transformed dI/dU maps we study scattering processes around defects and reveal that backscattering is forbidden for topological surface states. Based on bias-dependent measurements we determine the energy dispersion relation, the position of the Dirac point, and the carrier velocity. We also show that, by moving away from the Dirac point, the linear dispersion relation—which is typical for massless Dirac fermions—does not hold anymore. Instead, strong warping effects can be detected.