Informace o publikaci

Nonmagnetic band gap at the Dirac point of the magnetic topological insulator (Bi1-xMnx)(2)Se-3

Autoři	SANCHEZ-BARRIGA J. VARYKHALOV A. SPRINGHOLZ G. STEINER H. KIRCHSCHLAGER R. BAUER G. CAHA Ondřej SCHIERLE E. WESCHKE E. UENAL A. A. VALENCIA S. DUNST M. BRAUN J. EBERT H. MINAR J. GOLIAS E. YASHINA L. V. NEY A. HOLÝ Václav RADER O.
Rok publikování	2016
Druh	Článek v odborném periodiku
Časopis / Zdroj	Nature Communications
Fakulta / Pracoviště MU	Středoevropský technologický institut
Citace
www	http://www.nature.com/articles/ncomms10559
Doi	http://dx.doi.org/10.1038/ncomms10559
Obor	Fyzika pevných látek a magnetismus
Klíčová slova	SURFACE; FERROMAGNETISM; TRANSITION; GA1-XMNXAS; FERMIONS
Popis	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 (Bi1-xMnx)(2)Se-3 is a prototypical magnetic topological insulator with a pronounced surface band gap of similar to 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.