Experimental Discovery of Weyl Semimetal TaAs
Experimental Discovery of Weyl Semimetal TaAs
复制标题
外尔半金属 TaAs 的实验发现
DOI：
10.1103/physrevx.5.031013
复制
发表时间：
2015-07-31
影响因子：
12.5
通讯作者：
Ding, H.
中科院分区：
文献类型：
--
作者：
Lv, B. Q.;Weng, H. M.;Ding, H.
Weyl半金属是一类在打破时间反转或反转对称性后可以被视为石墨烯三维类似物的材料。Weyl半金属中的电子表现为Weyl费米子，具有许多奇异性质，如晶体动量空间中的手性异常和磁单极子。Weyl半金属的表面态在两个相对的表面显示一对纠缠的费米弧。然而，Weyl半金属的存在尚未得到实验证明。本文报道了一种Weyl半金属在TaAs中的实验实现，方法是利用角分辨光谱学观察其表面态形成的费米弧。我们的第一性原理计算与实验结果非常吻合，进一步证实了TaAs是一种Weyl半金属。
Weyl semimetals are a class of materials that can be regarded as three-dimensional analogs of graphene upon breaking time-reversal or inversion symmetry. Electrons in a Weyl semimetal behave as Weyl fermions, which have many exotic properties, such as chiral anomaly and magnetic monopoles in the crystal momentum space. The surface state of a Weyl semimetal displays pairs of entangled Fermi arcs at two opposite surfaces. However, the existence of Weyl semimetals has not yet been proved experimentally. Here, we report the experimental realization of a Weyl semimetal in TaAs by observing Fermi arcs formed by its surface states using angle-resolved photoemission spectroscopy. Our first-principles calculations, which match remarkably well with the experimental results, further confirm that TaAs is a Weyl semimetal.