A topological insulator surface under strong Coulomb, magnetic and disorder perturbations

L. Andrew Wray, Su Yang Xu, Yuqi Xia, David Hsieh, Alexei V. Fedorov, Yew San Hor, Robert J. Cava, Arun Bansil, Hsin Lin, M. Zahid Hasan

    Research output: Contribution to journalArticlepeer-review


    Topological insulators embody a state of bulk matter characterizedby spin-momentum-locked surface states that span the bulk bandgap. This highly unusual surface spin environment provides a rich ground for uncovering new phenomena. Understanding the response of a topological surface to strong Coulomb perturbations represents a frontier in discovering the interacting and emergent many-body physics of topological surfaces. Here we present the first controlled study of topological insulator surfaces under Coulomb and magnetic perturbations. We have used time-resolved deposition of iron, with a large Coulomb charge and significant magnetic moment, to systematically modify the topological spin structure of the Bi 2 Se 3 surface. We observe that such perturbation leads to the creation of odd multiples of Dirac fermions and that magnetic interactions break time-reversal symmetry in the presence of band hybridizations. We present a theoretical model to account for the observed electron dynamics of the topological surface. Taken collectively, these results are a critical guide in controlling electron mobility and quantum behaviour of topological surfaces, not only for device applications but also in setting the stage for creating exotic particles such as axions or imaging monopoles on the surface.

    Original languageEnglish (US)
    Pages (from-to)32-37
    Number of pages6
    JournalNature Physics
    Issue number1
    StatePublished - Jan 2011

    ASJC Scopus subject areas

    • General Physics and Astronomy


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