Weyl semimetal phase in the non-centrosymmetric compound TaAs
2015; Nature Portfolio; Volume: 11; Issue: 9 Linguagem: Inglês
10.1038/nphys3425
ISSN1745-2481
AutoresLexian Yang, Zhongkai Liu, Yan Sun, Han Peng, Haifeng Yang, Tingwei Zhang, Bo Zhou, Yi Zhang, Yanfeng Guo, M. C. Rahn, D. Prabhakaran, Z. Hussain, Sung‐Kwan Mo, Claudia Felser, Binghai Yan, Yulin Chen,
Tópico(s)Advanced Condensed Matter Physics
ResumoExperiments show that TaAs is a three-dimensional topological Weyl semimetal. Three-dimensional (3D) topologicalWeyl semimetals (TWSs) represent a state of quantum matter with unusual electronic structures that resemble both a ‘3D graphene’ and a topological insulator. Their electronic structure displays pairs of Weyl points (through which the electronic bands disperse linearly along all three momentum directions) connected by topological surface states, forming a unique arc-like Fermi surface (FS). Each Weyl point is chiral and contains half the degrees of freedom of a Dirac point, and can be viewed as a magnetic monopole in momentum space. By performing angle-resolved photoemission spectroscopy on the non-centrosymmetric compound TaAs, here we report its complete band structure, including the unique Fermi-arc FS and linear bulk band dispersion across the Weyl points, in agreement with the theoretical calculations1,2. This discovery not only confirms TaAs as a 3DTWS, but also provides an ideal platform for realizing exotic physical phenomena (for example, negative magnetoresistance, chiral magnetic effects and the quantum anomalous Hall effect) which may also lead to novel future applications.
Referência(s)