Graphene-based topological insulator with an intrinsic bulk band gap above room temperature

Kou L, Yan B, Hu F, Wu SC, Wehling TO, Felser C, Chen C, Frauenheim T (2013)

Publication Type: Journal article

Publication year: 2013

Journal

Nano Letters American Chemical Society

Book Volume: 13

Pages Range: 6251-6255

Journal Issue: 12

DOI: 10.1021/nl4037214

Abstract

Topological insulators (TIs) represent a new quantum state of matter characterized by robust gapless states inside the insulating bulk gap. The metallic edge states of a two-dimensional (2D) TI, known as the quantum spin Hall (QSH) effect, are immune to backscattering and carry fully spin-polarized dissipationless currents. However, existing 2D TIs realized in HgTe and InAs/GaSb suffer from small bulk gaps (<10 meV) well below room temperature, thus limiting their application in electronic and spintronic devices. Here, we report a new 2D TI comprising a graphene layer sandwiched between two Bi 2Se3 slabs that exhibits a large intrinsic bulk band gap of 30-50 meV, making it viable for room-temperature applications. Distinct from previous strategies for enhancing the intrinsic spin-orbit coupling effect of the graphene lattice, the present graphene-based TI operates on a new mechanism of strong inversion between graphene Dirac bands and Bi2Se 3 conduction bands. Strain engineering leads to effective control and substantial enhancement of the bulk gap. Recently reported synthesis of smooth graphene/Bi2Se3 interfaces demonstrates the feasibility of experimental realization of this new 2D TI structure, which holds great promise for nanoscale device applications. © 2013 American Chemical Society.

Involved external institutions

Universität Bremen DE Germany (DE) Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) University of Nevada Las Vegas US United States (USA) (US)

How to cite

APA:

Kou, L., Yan, B., Hu, F., Wu, S.-C., Wehling, T.O., Felser, C.,... Frauenheim, T. (2013). Graphene-based topological insulator with an intrinsic bulk band gap above room temperature. Nano Letters, 13(12), 6251-6255. https://doi.org/10.1021/nl4037214

MLA:

Kou, Liangzhi, et al. "Graphene-based topological insulator with an intrinsic bulk band gap above room temperature." Nano Letters 13.12 (2013): 6251-6255.

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