Charge-to-Spin Interconversion in Low-Symmetry Topological Materials

ORAL

Abstract

We theoretically show that the reduced symmetry of strong spin-orbit coupling materials such as MoTe2 or WTe2 enables a new form of oblique spin Hall effect (SHE), characterized by large and robust in-plane spin polarizations. Through quantum transport calculations on realistic device geometries, including disorder, we found long spin diffusion lengths (λs) and a gate tunable charge-to-spin interconversion efficiency with an upper value reaching θxy ∼ 80%. The SHE figure of merit λsθxy ∼ 1-50 nm, can significantly exceed values of conventional SHE materials, and stems from momentum invariant (persistent) spin textures together with large spin Berry curvature along the Fermi contour. Specific guidelines for unambiguous experimental confirmation are proposed, paving the way towards exploiting such phenomena in spintronic devices.

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Presenters

  • Marc Vila Tusell

    • Institut Català de Nanociència i Nanotecnologia (ICN2)

Authors

  • Marc Vila Tusell

    • Institut Català de Nanociència i Nanotecnologia (ICN2)

  • 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

  • Jose H. Garcia

    • Institut Català de Nanociència i Nanotecnologia (ICN2)

  • L. Antonio Benítez

    • Institut Català de Nanociència i Nanotecnologia (ICN2)

  • 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

  • Sergio Valenzuela

    • Institut Català de Nanociència i Nanotecnologia (ICN2), ICREA
    • ICREA and Catalan Institute of Nanoscience and Nanotechnology

  • 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