Dirac nodal-line semimetals with the linear bands crossing along a line or loop, represent a new topological state of matter. Here, by carrying out magnetotransport measurements and performing first-principle calculations, we demonstrate that such a state has been realized in high-quality single crystals of SrAs₃. We obtain the nontrivial π$\pi$ Berry phase by analysing the Shubnikov-de Haas quantum oscillations. We also observe a robust negative longitudinal magnetoresistance induced by the chiral anomaly. Accompanying first-principles calculations identifies that a single hole pocket enclosing the loop nodes is responsible for these observations.

中文翻译：

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SrAs _3中Dirac节点线半金属的证据

线性带沿一条线或一条环相交的狄拉克节点线半金属代表了一种新的拓扑状态。在这里，通过进行磁迁移测量并进行第一性原理计算，我们证明了在SrAs ₃的高质量单晶中已经实现了这种状态。我们得到非平凡的π$\pi$通过分析Shubnikov-de Haas量子振荡来确定贝里相。我们还观察到由手性异常引起的强大的负纵向磁阻。伴随着第一性原理的计算表明，围绕这些环结的单个孔穴负责这些观察。