Magnetic and topological transitions in three-dimensional topological Kondo insulator
Magnetic and topological transitions in three-dimensional topological Kondo insulator
复制标题
三维拓扑近藤绝缘体中的磁和拓扑转变
DOI：
10.1088/0256-307x/35/12/127501
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发表时间：
2018
影响因子：
3.5
通讯作者：
Zhong Yin
中科院分区：
文献类型：
--
作者：
Li Huan;Wang Zhi-Yong;Zheng Xiao-Jun;Liu Yu;Zhong Yin
利用扩展的从玻色子方法，绘制了三维拓扑近藤绝缘体（TKI）中磁相和顺磁（PM）拓扑绝缘相（TI$_s$）的全局相图.通过引入电子跳变（EH）到第三近邻，我们识别出四个强拓扑绝缘（STI）相和两个弱拓扑绝缘（WTI）相，并将它们之间的拓扑跃迁的PM相图描述为EH、f电子能级和杂化常数的函数.我们还发现了绝缘体-金属过渡从STI相，具有表面费米环和自旋纹理定性协议TKI候选人SmB$_6$。在弱杂化区，反铁磁（AF）有序自然出现在相图中，根据磁性边界如何穿过PM拓扑过渡线，AF相根据它们的$\mathcal{Z} 2 $指数被分为AF拓扑绝缘体（AFTI）和非拓扑AF绝缘体（nAFI）.在参数空间的两个小区域中，AF相位之间发生两个不同的拓扑过渡过程，导致两种类型的AFTI，显示出可区分的表面色散周围的狄拉克点。
By using an extended slave-boson method, we draw a global phase diagram summarizing both magnetic phases and paramagnetic (PM) topological insulating phases (TI$_s$) in three-dimensional topological Kondo insulator (TKI). By including electron hopping (EH) up to third neighbor, we identify four strong topological insulating (STI) phases and two weak topological insulating (WTI) phases, then the PM phase diagrams characterizing topological transitions between these TI$_s$ are depicted as functions of EH, $f$-electron energy level and hybridization constant. We also find an insulator-metal transition from a STI phase which has surface Fermi rings and spin textures in qualitative agreement to TKI candidate SmB$_6$. In weak hybridization regime, antiferromagnetic (AF) order naturally arises in the phase diagrams, and depending on how the magnetic boundary crosses the PM topological transition lines, AF phases are classified into AF topological insulator (AFTI) and non-topological AF insulator (nAFI), according to their $\mathcal{Z}_2$ indices. In two small regions of parameter space, two distinct topological transition processes between AF phases occur, leading to two types of AFTI, showing distinguishable surface dispersions around their Dirac points.