FisMat2017 - Submission - View

Abstract's title: Magnetic exchange on the surface of topological insulators
Submitting author: Alessandro Barla
Affiliation: ISM-CNR Trieste
Affiliation Address: S.S. 14 Km 163.5, I-34149 Trieste Basovizza (TS), Italy
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Sanjoy K. Mahatha (ISM-CNR Trieste), Paolo Sessi (Universität Würzburg), Kai Fauth (Universität Würzburg), Thomas Bathon (Universität Würzburg), Matthias Bode (Universität Würzburg), Miguel Angel Valbuena (Catalan Institute of Nanoscience and Nanotechnology, Barcelona), Sylvie Godey (Catalan Institute of Nanoscience and Nanotechnology, Barcelona), Aitor Mugarza (Catalan Institute of Nanoscience and Nanotechnology, Barcelona), Pierluigi Gargiani (ALBA Synchrotron Light Source, Barcelona), Philipp Rüßmann (PGI-1 and IAS-1, Forschungszentrum Jülich and JARA, Jülich), Phivos Mavropoulos (PGI-1 and IAS-1, Forschungszentrum Jülich and JARA, Jülich), Gustav Bihlmayer (PGI-1 and IAS-1, Forschungszentrum Jülich and JARA, Jülich), Stefan Blügel (PGI-1 and IAS-1, Forschungszentrum Jülich and JARA, Jülich), Carlo Carbone (ISM-CNR Trieste)
Abstract

Three-dimensional topological insulators have conducting surface states in the bulk band gap, protected by time-reversal symmetry, which locks spin with momentum. It was shown, however, that surface magnetic doping can break time-reversal symmetry and induces backscattering of Dirac states [1]. We present the results of our investigations of the magnetic properties of individual atoms of 3d transition metals (Mn, Fe, Co) deposited on the surface of the topological insulator Bi2Te3. All studied adatoms present an out-of-plane magnetic anisotropy associated with sizeable orbital moments and we find evidence of surface-mediated magnetic exchange interactions which are of opposite sign for Mn and Co, as a result of the competition of several exchange mechanisms.
[1] P. Sessi et al., Nat. Commun. 5, 5349 (2014).