title: Nonmagnetic band gap at the Dirac point of the magnetic topological insulator (Bi(1-x)Mn(x))2Se3.
abstract: Magnetic doping is expected to open a band gap at the Dirac point of topological insulators by breaking time-reversal symmetry and to enable novel topological phases. Epitaxial (Bi(1-x)Mn(x))2Se3 is a prototypical magnetic topological insulator with a pronounced surface band gap of ∼100 meV. We show that this gap is neither due to ferromagnetic order in the bulk or at the surface nor to the local magnetic moment of the Mn, making the system unsuitable for realizing the novel phases. We further show that Mn doping does not affect the inverted bulk band gap and the system remains topologically nontrivial. We suggest that strong resonant scattering processes cause the gap at the Dirac point and support this by the observation of in-gap states using resonant photoemission. Our findings establish a mechanism for gap opening in topological surface states which challenges the currently known conditions for topological protection.
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sánchez-Barriga
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Varykhalov
authors.affiliation: Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, 4040 Linz, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Springholz
authors.affiliation: Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, 4040 Linz, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Steiner
authors.affiliation: Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, 4040 Linz, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Kirchschlager
authors.affiliation: Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, 4040 Linz, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Bauer
authors.affiliation: Department of Condensed Matter Physics, CEITEC, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.
authors.forename: O
authors.initials: O
authors.lastname: Caha
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Schierle
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Weschke
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: A A
authors.initials: AA
authors.lastname: Ünal
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Valencia
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Dunst
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Braun
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Ebert
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany.|New Technologies Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Minár
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Golias
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia.
authors.forename: L V
authors.initials: LV
authors.lastname: Yashina
authors.affiliation: Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, Altenbergerstr. 69, 4040 Linz, Austria.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-2388-6006
authors.initials: A
authors.lastname: Ney
authors.affiliation: Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 12116 Prague, Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Holý
authors.affiliation: Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Rader