PT - JOURNAL ARTICLE
AU - Zhang, Jinsong
AU - Chang, Cui-Zu
AU - Tang, Peizhe
AU - Zhang, Zuocheng
AU - Feng, Xiao
AU - Li, Kang
AU - Wang, Li-li
AU - Chen, Xi
AU - Liu, Chaoxing
AU - Duan, Wenhui
AU - He, Ke
AU - Xue, Qi-Kun
AU - Ma, Xucun
AU - Wang, Yayu
TI - Topology-Driven Magnetic Quantum Phase Transition in Topological Insulators
AID - 10.1126/science.1230905
DP - 2013 Mar 29
TA - Science
PG - 1582--1586
VI - 339
IP - 6127
4099 - http://science.sciencemag.org/content/339/6127/1582.short
4100 - http://science.sciencemag.org/content/339/6127/1582.full
SO - Science2013 Mar 29; 339
AB - Topological insulators owe their exotic properties to the peculiarities of their band structure, and one can induce a transition between a topologically trivial and nontrivial material by chemical doping. Now, J. Zhang et al. (p. 1582) have gone a step furtherâ€”simultaneously observing that a magnetic quantum transition as the ratio of Se and Te is varied in Bi2(SexTe1-x)3 thin films grown by molecular beam epitaxy and doped with magnetic Cr. Photoemission and transport experiments, as well as density functional calculations, imply that the topological transition induces magnetismThe 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.