The recent discovery of the first Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature. Such a topological semimetal features a novel type of anomalous surface state, the Fermi arc, which connects a pair of Weyl nodes through the boundary of the crystal. Here, we present theoretical calculations of the quasi-particle interference (QPI) patterns that arise from the surface states including the topological Fermi arcs in the Weyl semimetals TaAs and NbP. Most importantly, we discover that the QPI exhibits termination-points that are fingerprints of the Weyl nodes in the interference pattern. Our results, for the first time, propose an interference signature of the topological Fermi arcs in TaAs, which provides important guidelines for STM measurements on this prototypical Weyl semimetal compound. The scattering channels presented here is relevant to transport phenomena on the surface of the TaAs class of Weyl semimetals. Our work is also the first systematic calculation of the quantum interferences from the Fermi arc surface states, which is in general useful for future STM studies on other Weyl semimetals.

翻译：最近在TaAs中发现了第一个Weyl 半金属体,这是对自然界的Weyl fermion的首次观测。这样的表层半金属体具有新型异常表面状态的新颖类型,即Fermi arc,它通过水晶的边界将一对Weyl 结点连接起来。这里,我们提出对来自表面状态的准粒子干扰(QPI)模式的理论计算,包括Weyl 半金属体Taas和NbP的表层Fermi 弧。最重要的是,我们发现QPI展示了作为干扰形态中Wyl 结点的指纹的终止点。我们的结果首次提出了TaAs的表层红铁弧的干扰特征,为STM测量这种原状Wyl 半金属化合物提供了重要的准则。这里介绍的散射通道与TaAs 类Weyl 半金属体表面的迁移现象有关。我们的工作也是对Fermi rcal 半金属表面其他状态的量干扰进行首次系统计算,这是一般的SM 。