title: Exchange-coupling-induced symmetry breaking in topological insulators.
abstract: An exchange gap in the Dirac surface states of a topological insulator (TI) is necessary for observing the predicted unique features such as the topological magnetoelectric effect as well as to confine Majorana fermions. We experimentally demonstrate proximity-induced ferromagnetism in a TI, combining a ferromagnetic insulator EuS layer with Bi(2)Se(3), without introducing defects. By magnetic and magnetotransport studies, including anomalous Hall effect and magnetoresistance measurements, we show the emergence of a ferromagnetic phase in TI, a step forward in unveiling their exotic properties.
authors.affiliation: Francis Bitter Magnet Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. pwei@mit.edu
authors.forename: Peng
authors.initials: P
authors.lastname: Wei
authors.forename: Ferhat
authors.initials: F
authors.lastname: Katmis
authors.forename: Badih A
authors.initials: BA
authors.lastname: Assaf
authors.forename: Hadar
authors.initials: H
authors.lastname: Steinberg
authors.forename: Pablo
authors.initials: P
authors.lastname: Jarillo-Herrero
authors.forename: Donald
authors.initials: D
authors.lastname: Heiman
authors.forename: Jagadeesh S
authors.initials: JS
authors.lastname: Moodera