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arXiv · 1202.5636

Dirac semimetal and topological phase transitions in A3Bi (A=Na, K, Rb)

Zhijun Wang·Yan Sun·Xingqiu Chen·Cesare Franchini·Gang Xu·Hongming Weng·Xi Dai·Zhong Fang
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Abstract

The 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 non-trivial 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.

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Zhijun Wang, Yan Sun, Xingqiu Chen, Cesare Franchini, Gang Xu, Hongming Weng, Xi Dai, Zhong Fang. 2012-02-25. Dirac semimetal and topological phase transitions in A3Bi (A=Na, K, Rb). https://doi.org/10.1103/physrevb.85.195320

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