TY  - JOUR
A1  - Brüne, Christoph
A1  - Thienel, Cornelius
A1  - Stuiber, Michael
A1  - Böttcher, Jan
A1  - Buhmann, Hartmut
A1  - Novik, Elena G.
A1  - Liu, Chao-Xing
A1  - Hankiewicz, Ewelina M.
A1  - Molenkamp, Laurens W.
T1  - Dirac-Screening Stabilized Surface-State Transport in a Topological Insulator
T2  - Physical Review X
N2  - We report magnetotransport studies on a gated strained HgTe device. This material is a three-dimensional topological insulator and exclusively shows surface-state transport. Remarkably, the Landau-level dispersion and the accuracy of the Hall quantization remain unchanged over a wide density range (3×1011  cm−2<n<2×1012  cm−2). These observations imply that even at large carrier densities, the transport is surface-state dominated, where bulk transport would have been expected to coexist already. Moreover, the density dependence of the Dirac-type quantum Hall effect allows us to identify the contributions from the individual surfaces. A k⋅p model can describe the experiments but only when assuming a steep band bending across the regions where the topological surface states are contained. This steep potential originates from the specific screening properties of Dirac systems and causes the gate voltage to influence the position of the Dirac points rather than that of the Fermi level.
KW  - condensed matter physics
KW  - topological insulators
Y1  - 2014
UR  - https://opus.bibliothek.uni-wuerzburg.de/opus4-wuerzburg/frontdoor/index/index/docId/11809
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-118091
SN  - 2160-3308
VL  - 4
IS  - 4
ER  -