How disorder affects topological surface states in the limit of ultrathin Bi<inf>2</inf>Se<inf>3</inf> films

Kenan Song, David Soriano, Roberto Robles, Pablo Ordejon, Stephan Roche

    Research output: Contribution to journalArticleResearchpeer-review

    1 Citation (Scopus)

    Abstract

    © 2016 IOP Publishing Ltd. We present a first-principles study of electronic properties of ultrathin films of topological insulators (TIs) and scrutinize the role of disorder on the robustness of topological surface states, which can be analysed through their spin textures. The presence of twin grain boundaries is found to increase the band gap of the film, while preserving the spin texture of states in first conduction and valence bands. Differently, partial hydrogenation of one surface not only results in some self-doping effect, but also provokes some alteration of the spin texture symmetry of the electronic states. The formation of a new Dirac cone at M-point of the Brillouin zone of the hydrogenated surface, together with a modified spin texture characteristics are consistent with a dominant Dresselhaus spin-orbit interaction type, more usually observed in 3D materials. Our findings indicate that defects can either be detrimental or beneficial for exploring spin transport of surface states in the limit of ultrathin films of TIs, which maximizes surface over bulk phenomena.
    Original languageEnglish
    Article number045007
    Journal2D materials
    Volume3
    Issue number4
    DOIs
    Publication statusPublished - 7 Oct 2016

    Keywords

    • Disorder effects
    • Spin texture
    • Topological insulators
    • Ultrathin films

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