Dresden 2014 – scientific programme
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MA: Fachverband Magnetismus
MA 49: Poster: Topological insulators (with O,TT)
MA 49.6: Poster
Thursday, April 3, 2014, 17:00–20:00, P1
Weak anti-localization in HgTe quantum wire arrays — •Johannes Ziegler1, Sabine Weishäupl1, Christopher Ames2, Christoph Brüne2, Harmut Buhmann2, Laurens W. Molenkamp2, and Dieter Weiss1 — 1Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Germany — 2Physikalisches Institut (EP III), Universität Würzburg, Germany
We present our progress in fabricating quasi-1D quantum wire arrays in inverted HgTe quantum wells, being a 2D topological insulator. These quasi-1D quantum wire arrays were fabricated with widths between 120 nm and 250 nm. Our experiments focus on phase-coherent effects, like weak anti-localization and weak-localization, in both wire arrays and 15 and 40 µm wide Hall-bars. From these measurements we extract the phase-coherence length lφ and the spin-relaxation length lSO.
Our work is motivated by a proposal for all-electrical detection of the relative spin-orbit interaction strength α / β [1,2], where α is the Rashba and β the Dresselhaus spin-orbit parameter. A key requirement for this method is the transition from weak anti-localization (WAL) to weak localization (WL) through 1D confinement. The analysis of these characteristic lengths allows us to check when the suppression of WAL occurs.
[1] M. Scheid et al., Phys. Rev. L 101, 266401 (2008).
[1] M. Scheid et al., Semicond. Sci. Technol. 24, 064005 (2009).