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

By L. Wray, Su-Yang Xu, Yuqi Xia, D. Hsieh, A. Fedorov, Hsin Lin, Arun Bansil, Y. Hor, R. Cava, M. Zahid Hasan. 2011

462 citations recorded by the source corpus.

Topological insulators embody a state of bulk matter characterized by 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_2Se_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.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/f76d445f45350d00bad90cace328edeb0fe6eac8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. Pietro Gambardella
2. J. Sinova
3. T. Jungwirth
4. A. Manchon
5. I. Miron
6. Kevin Garello
7. A. Thiaville
8. J. Železný

In Condensed Matter Physics

1. J. Sinova
2. T. Jungwirth
3. Pietro Gambardella
4. I. Miron
5. Kevin Garello
6. J. Železný
7. A. Thiaville
8. Hsin Lin

Citations in the corpus

• Colloquium : Topological band theory (2016, background): “(Wray et al. 2011; Okada et al. 2011) The predicted suppression of backscattering channels (Fu 2009; Zhou et al.”
• Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems (2018, background): “which go beyond the simple notion of a magnetic exchange field breaking time reversal symmetry and opening a gap in the surface states (Wray et al., 2011).”
• Trajectory of the anomalous Hall effect towards the quantized state in a ferromagnetic topological insulator (2014, unknown): “This gap was observed by angle resolved photoemission spectroscopy (ARPES) experiments in both bulk [19] and surface [20] magnetically doped TIs.”