Canted Spin Texture and Quantum Spin Hall Effect in WTe<sub>2</sub>

ORAL

Abstract

We report an unconventional quantum spin Hall phase in the monolayer Td-WTe2, which exhibits hitherto unknown features in other topological materials. The low-symmetry of the structure in-duces a canted spin texture in theyzplane, which dictates the spin polarization of topologically protected boundary states. Additionally, the spin Hall conductivity gets quantized (2e2/h) witha spin quantization axis parallel to the canting direction. These findings are based on large-scale quantum simulations of the spin Hall conductivity tensor and nonlocal resistances in multi-probe geometries using a realistic tight-binding model elaborated from first-principle methods. The observation of this canted quantum spin Hall effect, related to the formation of topological edge stateswith nontrivial spin polarization, demands for specific experimental design and suggests interestingalternatives for manipulating spin information in topological materials.

*We acknowledges support from:
“La Caixa” Foundation, the ANR Flagera GRANSPORT funding, the EU2020 research and innovation programme Grant Agreement No. 881603 and No. 824140. The CERCA Programme/Generalitat de Catalunya, Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706). The NationalResearch Foundation (Singapore) (R-723-000-001-281).

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Presenters

  • José Garcia Aguilar

    • Computational and Theoretical Nanoscience group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain

Authors

  • José Garcia Aguilar

    • Computational and Theoretical Nanoscience group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain

  • Marc Vila

    • Computational and Theoretical Nanoscience group, Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain

  • Chuang-Han Hsu

    • Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
    • Institute of Physics, Academia Sinica, Taipei
    • Institute of Physics, Academia Sinica

  • Xavier Waintal

    • Univ. Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France
    • Université Grenoble Alpes
    • CEA Grenoble
    • Université Grenoble Alpes, CEA, IRIG-PHELIQS, 38000 Grenoble, France

  • Vitor Manuel Pereira

    • Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117576, Singapore
    • Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore

  • Stephan Roche

    • ICREA–Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
    • Institut Català de Nanociència i Nanotecnologia (ICN2), ICREA