Anomalous Z2 antiferromagnetic topological phase in pressurized SmB6

作     者：Kai-Wei Chang Peng-Jen Chen 

作者机构：Department of Physics National Taiwan University Taipei 10617 Taiwan Nano Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei 11529 Taiwan and National Taiwan University Taipei 10617 Taiwan Institute of Physics Academia Sinica Taipei 11529 Taiwan 

出 版 物：《Physical Review B》 (Phys. Rev. B)

年 卷 期：2018年第97卷第19期

页      面：195145-195145页

核心收录：

基　　金：Academia Sinica Ministerio de Ciencia y Tecnología, MICYT, (MOST 106-2119-M-001-028) 

主　　题：Antiferromagnetism First-principles calculations Topological phases of matter 

摘      要：Antiferromagnetic materials, whose time-reversal symmetry is broken, can be classified into the Z2 topology if they respect some specific symmetry. Since the theoretical proposal, however, no materials have been found to host such Z2 antiferromagnetic topological (Z2−AFT) phase to date. Here we demonstrate that the topological Kondo insulator SmB6 can be a Z2−AFT system when pressurized to undergo an antiferromagnetic phase transition. In addition to proposing the possible candidate for a Z2−AFT material, in this work we also illustrate the anomalous topological surface states of the Z2−AFT phase which have not been discussed before. Originating from the interplay between the topological properties and the antiferromagnetic surface magnetization, the topological surface states of the Z2−AFT phase behave differently as compared with those of a topological insulator. Besides, the Z2−AFT insulators are also found promising in the generation of tunable spin currents, which is an important application in spintronics.