Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 17: Transport: Topological insulators 1 (TT with DS/HL)
HL 17.3: Vortrag
Montag, 16. März 2015, 15:45–16:00, A 053
Intrinsic conduction through topological surface states of insulating Bi2Te3 epitaxial thin films — •Katharina Hoefer1, Christoph Becker1, Diana Rata1, Jesse Swanson1,2, Peter Thalmeier1, and Liu Hao Tjeng1 — 1Max Planck Institute for Chemical Physics of Solids, Dresden — 2University of British Columbia, Vancouver
Topological insulators represent a new state of matter that open up new opportunities to create unique quantum particles. Many exciting experiments have been proposed by theory, yet, the main obstacle for their execution is material quality and cleanliness of the experimental conditions. The presence of tiny amounts of defects in the bulk or contaminants at the surface already mask these phenomena.
We present the preparation, structural and spectroscopic characterisation of MBE-grown Bi2Te3 thin films that are insulating in the bulk. Moreover, temperature dependent four-point-probe resistivity measurements of the Dirac states on surfaces that are intrinsically clean were conducted. The total amount of surface charge carries is in the order of 1012 cm−2 and mobilities up to 4600 cm2/Vs are observed.
Importantly, these results are achieved by carrying out the preparation and characterisation all in-situ under ultra-high-vacuum conditions [1].
[1] K. Hoefer et al. PNAS, 2014, 111(42), 14979-14984.