Dresden 2014 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 105: Poster: Topological insulators (with MA/O)
HL 105.9: Poster
Donnerstag, 3. April 2014, 17:00–20:00, P1
Transport properties of the high mobility topological insulator HgTe — •Jonas Wiedenmann1, Cornelius Thienel1, Christopher Ames1, Christopher Brüne1, Steffen Wiedmann2, Hartmut Buhmann1, and Laurens Molenkamp1 — 1Universität Würzburg, Würzburg, Deutschland — 2Radboud Universität Nijmegen, Nijmegen, Holland
It has been demonstrated recently, that the semimetal HgTe opens a band gap of approximately 20 meV when grown strained on a CdTe substrate and thus becomes a three dimensional topological insulator (3D TI)[1].
We show that it is possible to increase the mobility of the surface states by an order of magnitude, if HgTe is sandwiched between epitaxial layers of HgCdTe. The topological insulator is investigated in transport measurements at low temperatures and magnetic fields up to 30 T. Through the enhanced surface mobilites we are able to observe a Dirac specific quantum hall effect. The experimental data suggest, that it has to be discussed within a two surface model for Dirac fermions.
[1] C. Brüne et al., Phys. Rev. Lett. 106, 126803 (2011)