Weyl (WSMs) evolve from Dirac semimetals in the presence of broken time-reversal symmetry (TRS) or space-inversion symmetry. The WSM phases in TaAs-class materials and photonic crystals are due to the loss of space-inversion symmetry. For TRS-breaking WSMs, despite numerous theoretical and experimental efforts, few examples have been reported. In this Article, we report a new type of magnetic semimetal Sr_1−yMn_1−zSb₂ (y, z < 0.1) with nearly massless relativistic fermion behaviour (m^∗ =  0.04 − 0.05m₀, where m₀ is the free-electron mass). This material exhibits a ferromagnetic order for 304 K  <  T  <  565 K, but a canted antiferromagnetic order with a ferromagnetic component for T  <  304 K. The combination of relativistic fermion behaviour and ferromagnetism in Sr_1−yMn_1−zSb₂ offers a rare opportunity to investigate the interplay between relativistic fermions and spontaneous TRS breaking.

中文翻译：

---

磁性拓扑半金属Sr1-yMn1-zSb2（y，z <0.1）

Weyl（WSMs）是在存在时间逆转对称性（TRS）或空间反转对称性的情况下从狄拉克半金属演化而来的。TaAs类材料和光子晶体中的WSM相归因于空间反转对称性的丧失。对于突破TRS的WSM，尽管进行了许多理论和实验性的努力，但几乎没有报道过这样的例子。在本文中，我们报告了一种新型的磁性半金属Sr _{1- y} Mn _{1- z} Sb ₂（y，z <0.1），具有近乎无质量的相对论性费米子行为（m ^∗ = 0.04-0.05 m ₀，其中m ₀是自由电子质量）。这种材料显示出铁磁有序304  ķ<   Ť   <565  K，而是倾斜的反铁磁顺序与用于铁磁部件Ť   <304  K的相对论费米子行为和铁磁性SR的组合_{1- ý}锰_{1- Ž}的Sb _2个报价一个难得的机会来研究相对论费米子与自发TRS断裂之间的相互作用。