title: Topology-driven magnetic quantum phase transition in topological insulators.
abstract: The breaking of time reversal symmetry in topological insulators may create previously unknown quantum effects. We observed a magnetic quantum phase transition in Cr-doped Bi2(SexTe1-x)3 topological insulator films grown by means of molecular beam epitaxy. Across the critical point, a topological quantum phase transition is revealed through both angle-resolved photoemission measurements and density functional theory calculations. We present strong evidence that the bulk band topology is the fundamental driving force for the magnetic quantum phase transition. The tunable topological and magnetic properties in this system are well suited for realizing the exotic topological quantum phenomena in magnetic topological insulators.
authors.affiliation: State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing, P R China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
authors.forename: Cui-Zu
authors.initials: CZ
authors.lastname: Chang
authors.forename: Peizhe
authors.initials: P
authors.lastname: Tang
authors.forename: Zuocheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Xiao
authors.initials: X
authors.lastname: Feng
authors.forename: Kang
authors.initials: K
authors.lastname: Li
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wang
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Chaoxing
authors.initials: C
authors.lastname: Liu
authors.forename: Wenhui
authors.initials: W
authors.lastname: Duan
authors.forename: Ke
authors.initials: K
authors.lastname: He
authors.forename: Qi-Kun
authors.initials: QK
authors.lastname: Xue
authors.forename: Xucun
authors.initials: X
authors.lastname: Ma
authors.forename: Yayu
authors.initials: Y
authors.lastname: Wang