Dirac semimetal and topological phase transitions in A3Bi (A = Na, K, Rb)
Dirac semimetal and topological phase transitions in A3Bi (A = Na, K, Rb)
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DOI：
10.1103/physrevb.85.195320
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发表时间：
2012-05-22
影响因子：
3.7
通讯作者：
Fang, Zhong
中科院分区：
文献类型：
--
作者：
Wang, Zhijun;Sun, Yan;Fang, Zhong
两个Weyl点在动量空间中重叠的三维Dirac点通常是不稳定的，难以实现。基于第一性原理计算和有效模型分析，我们证明了晶体A(3)Bi （A = Na， K, Rb）是具有体三维狄拉克点的Dirac半金属，具有晶体对称性。它们在表面上具有非平凡的费米弧，并且可以通过显式的对称性破缺被驱动到各种拓扑上不同的相位。这类化合物将具有巨大的抗磁性、线性量子磁电阻和量子自旋霍尔效应。
Three-dimensional (3D) Dirac point, where two Weyl points overlap in momentum space, is usually unstable and hard to realize. Here we show, based on the first-principles calculations and effective model analysis, that crystalline A(3)Bi (A = Na, K, Rb) are Dirac semimetals with bulk 3D Dirac points protected by crystal symmetry. They possess nontrivial Fermi arcs on the surfaces and can be driven into various topologically distinct phases by explicit breaking of symmetries. Giant diamagnetism, linear quantum magnetoresistance, and quantum spin Hall effect will be expected for such compounds.