Dirac-Screening Stabilized Surface-State Transport in a Topological Insulator
Please always quote using this URN: urn:nbn:de:bvb:20-opus-118091
- 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 theWe 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.…
Author: | Christoph Brüne, Cornelius Thienel, Michael Stuiber, Jan Böttcher, Hartmut Buhmann, Elena G. Novik, Chao-Xing Liu, Ewelina M. Hankiewicz, Laurens W. Molenkamp |
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URN: | urn:nbn:de:bvb:20-opus-118091 |
Document Type: | Journal article |
Faculties: | Fakultät für Physik und Astronomie / Institut für Theoretische Physik und Astrophysik |
Language: | English |
Parent Title (English): | Physical Review X |
ISSN: | 2160-3308 |
Year of Completion: | 2014 |
Volume: | 4 |
Issue: | 4 |
Pagenumber: | 041045 |
Source: | PHYSICAL REVIEW X 4, 041045 (2014). DOI: 10.1103/PhysRevX.4.041045 |
DOI: | https://doi.org/10.1103/PhysRevX.4.041045 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Tag: | condensed matter physics; topological insulators |
Release Date: | 2015/08/31 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung |