Magnetic-tunnelling-induced Weyl node annihilation in TaP

Zhang, Cheng-Long1; Xu, Su-Yang2; Wang, C. M.3,4,5; Lin, Ziquan6; Du, Z. Z.3,4,7; Guo, Cheng1; Lee, Chi-Cheng8,9,10; Lu, Hong1; Feng, Yiyang1; Huang, Shin-Ming8,9,10,11; Chang, Guoqing8,9,10; Hsu, Chuang-Han8,9,10; Liu, Haiwen1; Lin, Hsin8,9,10; Li, Liang; Zhang, Chi1,12; Zhang, Jinglei13; Xie, Xin-Cheng1,12; Neupert, Titus14; Hasan, M. Zahid2; Lu, Hai-Zhou3,4; Wang, Junfeng6; Jia, Shuang1,12

2017-10

10.1038/NPHYS4183

Nature Physics   影响因子和分区

1745-2473

1745-2481

Weyl nodes are topological objects in three-dimensional metals. Whereas the energy of the lowest Landau band of a conventional Fermi pocket increases with magnetic field due to the zero-point energy (1/2 h omega), the lowest Landau band of Weyl cones stays at zero energy unless a strong magnetic field couples Weyl fermions of opposite chirality. In the Weyl semimetal TaP, which possesses two types of Weyl nodes (four pairs of W1 and eight pairs of W2 nodes), we observed such a magnetic coupling between the electron pockets arising from the W1 Weyl fermions. As a result, their lowest Landau bands move above the chemical potential, leading to a sharp sign reversal in the Hall resistivity at a specific magnetic field corresponding to the separation in momentum space of the W1 Weyl nodes, root(eB/h) similar to Delta k(W1). By contrast, annihilation is not observed for the hole pocket because the separation of the W2 Weyl nodes is much larger. These findings reveal the nontrivial topology of Weyl fermions in high-field transport measurements and demonstrate the observation of Weyl node annihilation, which is a unique topological phenomenon associated with Weyl fermions.

SCI ; EI

英语

NI论文

通讯

National Science Foundation[DMR-1157490]

Physics

Physics, Multidisciplinary

WOS:000412181200019

NATURE PUBLISHING GROUP

20190806528760

Magnetic couplings ; Stereochemistry ; Topology

Mechanical Drives and Transmissions:602 ; Magnetism: Basic Concepts and Phenomena:701.2 ; Chemistry:801 ; Combinatorial Mathematics, Includes Graph Theory, Set Theory:921.4

Web of Science

1.Peking Univ, Sch Phys, Int Ctr Quantum Mat, Beijing 100871, Peoples R China
2.Princeton Univ, Dept Phys, Lab Topol Quantum Matter & Spect B7, Princeton, NJ 08544 USA
3.South Univ Sci & Technol China, Inst Quantum Sci & Engn, Shenzhen 518055, Peoples R China
4.South Univ Sci & Technol China, Dept Phys, Shenzhen 518055, Peoples R China
5.Anyang Normal Univ, Sch Phys & Elect Engn, Anyang 455000, Peoples R China
6.Huazhong Univ Sci & Technol, Wuhan Natl High Magnet Field Ctr, Wuhan 430074, Hubei, Peoples R China
7.Southeast Univ, Sch Phys, Nanjing 211189, Jiangsu, Peoples R China
8.Natl Univ Singapore, Ctr Adv Mat 2D, 6 Sci Dr 2, Singapore 117546, Singapore
9.Natl Univ Singapore, Graphene Res Ctr, 6 Sci Dr 2, Singapore 117546, Singapore
10.Natl Univ Singapore, Dept Phys, 2 Sci Dr 3, Singapore 117542, Singapore
11.Natl Sun Yat Sen Univ, Dept Phys, Kaohsiung 804, Taiwan
12.Collaborat Innovat Ctr Quantum Matter, Beijing 100871, Peoples R China
13.Chinese Acad Sci, Anhui Prov Key Lab Condensed Matter Phys Extreme, High Field Magnet Lab, Hefei 230031, Anhui, Peoples R China
14.Univ Zurich, Dept Phys, Winterthurerstr 190, CH-8052 Zurich, Switzerland

Zhang, Cheng-Long,Xu, Su-Yang,Wang, C. M.,et al. Magnetic-tunnelling-induced Weyl node annihilation in TaP[J]. Nature Physics,2017,13(10):979-+.

Zhang, Cheng-Long.,Xu, Su-Yang.,Wang, C. M..,Lin, Ziquan.,Du, Z. Z..,...&Jia, Shuang.(2017).Magnetic-tunnelling-induced Weyl node annihilation in TaP.Nature Physics,13(10),979-+.

Zhang, Cheng-Long,et al."Magnetic-tunnelling-induced Weyl node annihilation in TaP".Nature Physics 13.10(2017):979-+.