Evolution of the Fermi surface of Weyl semimetals in the transition metal pnictide family
Evolution of the Fermi surface of Weyl semimetals in the transition metal pnictide family
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DOI：
10.1038/nmat4457
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发表时间：
2016-01-01
期刊：
影响因子：
41.2
通讯作者：
Chen, Y. L.
中科院分区：
文献类型：
--
作者：
Liu, Z. K.;Yang, L. X.;Chen, Y. L.
拓扑外尔半金属 (TWS) 代表了一种新颖的拓扑量子物质态 (1-4)，它不仅拥有体相中的外尔费米子（无质量手性粒子，可被视为动量空间中的磁单极子）和由拓扑表面态产生的独特费米弧，而且还表现出极具吸引力的物理特性，例如极大的磁阻和超高载流子迁移率 (5-8)。在这里，通过对 NbP 和 TaP 进行角分辨光电子能谱 (ARPES)，我们直接观察了它们具有 TWS 特征费米弧的能带结构。此外，通过系统地研究来自同一过渡金属单硝化物家族的 NbP、TaP 和 TaAs，我们发现了它们随自旋轨道耦合 (SOC) 强度的费米学演化。我们的实验结果不仅揭示了实现和微调TWS电子结构的机制，而且为探索许多奇异的物理现象（例如手性磁效应、负磁阻和量子反常霍尔效应）和新颖的未来应用提供了丰富的物质基础(3,4,9-11)。
Topological Weyl semimetals (TWSs) represent a novel state of topological quantum matter(1-4) which not only possesses Weyl fermions (massless chiral particles that can be viewed as magnetic monopoles in momentum space) in the bulk and unique Fermi arcs generated by topological surface states, but also exhibits appealing physical properties such as extremely large magnetoresistance and ultra-high carrier mobility(5-8). Here, by performing angle-resolved photoemission spectroscopy (ARPES) on NbP and TaP, we directly observed their band structures with characteristic Fermi arcs of TWSs. Furthermore, by systematically investigating NbP, TaP and TaAs from the same transition metal monopnictide family, we discovered their Fermiology evolution with spin-orbit coupling (SOC) strength. Our experimental findings not only reveal the mechanism to realize and fine-tune the electronic structures of TWSs, but also provide a rich material base for exploring many exotic physical phenomena (for example, chiral magnetic effects, negative magnetoresistance, and the quantum anomalous Hall effect) and novel future applications(3,4,9-11).