Time-reversal symmetry breaking type-II Weyl state in YbMnBi2
Time-reversal symmetry breaking type-II Weyl state in YbMnBi2
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DOI：
10.1038/s41467-019-11393-5
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发表时间：
2019-07-31
影响因子：
16.6
通讯作者：
Cava, Robert J.
中科院分区：
文献类型：
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作者：
Borisenko, Sergey;Evtushinsky, Daniil;Cava, Robert J.
真实的材料中狄拉克和外尔费米子的光谱探测对于高能物理和凝聚态物理之间的基础桥梁和有前途的应用都是至关重要的。虽然狄拉克费米子和非中心对称外尔费米子在许多材料中的存在已经得到了很好的证实，但磁性外尔半金属仍然逃脱了直接的实验检测。为了找到一个时间反演对称性破缺Weyl状态，我们设计了两种材料，并在这里提出了实验和理论证据，实现这样的状态在其中之一，YbMnBi 2。我们通过倾斜反铁磁性对磁化和磁光显微镜测量观察到的时间反转对称性破缺进行了建模，并找到了许多外尔点。利用角分辨光电子能谱，我们直接观察到由费米弧连接的两对外尔点。我们的研究结果不仅提供了物理学的两个领域之间的基本联系，但也展示了实用的方法来设计具有奇异特性的新材料。
Spectroscopic detection of Dirac and Weyl fermions in real materials is vital for both, promising applications and fundamental bridge between high-energy and condensed-matter physics. While the presence of Dirac and noncentrosymmetric Weyl fermions is well established in many materials, the magnetic Weyl semimetals still escape direct experimental detection. In order to find a time-reversal symmetry breaking Weyl state we design two materials and present here experimental and theoretical evidence of realization of such a state in one of them, YbMnBi2. We model the time-reversal symmetry breaking observed by magnetization and magneto-optical microscopy measurements by canted antiferromagnetism and find a number of Weyl points. Using angle-resolved photoemission, we directly observe two pairs of Weyl points connected by the Fermi arcs. Our results not only provide a fundamental link between the two areas of physics, but also demonstrate the practical way to design novel materials with exotic properties.