journal article·2020-04Open access

Emergence of Nontrivial Low‐Energy Dirac Fermions in Antiferromagnetic EuCd2As2

Junzhang Ma, Han Wang, Simin Nie, Changjiang Yi, Yuanfeng Xu, Hang Li, Jasmin Jandke, Wulf Wulfhekel, Yaobo Huang, Damien West, Pierre Richard, Alla Chikina, Vladimir N. Strocov, Joël Mesot, Hongming Weng, Shengbai Zhang, Youguo Shi, Tian Qian, Ming Shi, Hong Ding

Advanced Materials· Volume 32· Issue 14

Abstract

Abstract Parity‐time symmetry plays an essential role for the formation of Dirac states in Dirac semimetals. So far, all of the experimentally identified topologically nontrivial Dirac semimetals (DSMs) possess both parity and time reversal symmetry. The realization of magnetic topological DSMs remains a major issue in topological material research. Here, combining angle‐resolved photoemission spectroscopy with density functional theory calculations, it is ascertained that band inversion induces a topologically nontrivial ground state in EuCd2As2. As a result, ideal magnetic Dirac fermions with simplest double cone structure near the Fermi level emerge in the antiferromagnetic (AFM) phase. The magnetic order breaks time reversal symmetry, but preserves inversion symmetry. The double degeneracy of the Dirac bands is protected by a combination of inversion, time‐reversal, and an additional translation operation. Moreover, the calculations show that a deviation of the magnetic moments from the c‐axis leads to the breaking of C3 rotation symmetry, and thus, a small bandgap opens at the Dirac point in the bulk. In this case, the system hosts a novel state containing three different types of topological insulator: axion insulator, AFM topological crystalline insulator (TCI), and higher order topological insulator. The results provide an enlarged platform for the quest of topological Dirac fermions in a magnetic system.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Topological Materials and Phenomena · Graphene research and applications · Advanced Condensed Matter Physics

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Paul Scherrer Institute Swiss Light Source CH‐5232 Villigen PSI Switzerland

Institute of Condensed Matter Physics École Polytechnique Fédérale de Lausanne CH‐10 15 Lausanne Switzerland

Department of Physics Applied Physics, and Astronomy Rensselaer Polytechnic Institute Troy NY 12180 USA

Department of Materials Science and Engineering Stanford University Stanford CA 94305 USA

Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China

School of Physics University of Chinese Academy of Sciences Beijing 100190 China

Physikalisches Institut Karlsruhe Institute of Technology 76131 Karlsruhe Germany

Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201204 China

Institut quantique Université de Sherbrooke 2500 boulevard de l'Université Sherbrooke Québec J1K 2R1 Canada

Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China

CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Beijing 100190 China

Funding

National Natural Science Foundation of China · Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung · Chinese Academy of Sciences · K. C. Wong Education Foundation · Beijing Municipal Science and Technology Commission · U.S. Department of Energy · National Science Foundation · Canada First Research Excellence Fund

References (48)

Show source-provided references
1. 10.1103/PhysRevB.85.19532010.1103/PhysRevB.85.195320 ↗
2. 10.1126/science.124508510.1126/science.1245085 ↗
3. 10.1103/PhysRevB.88.12542710.1103/PhysRevB.88.125427 ↗
4. 10.1038/nmat399010.1038/nmat3990 ↗
5. Weng H. · Phys. Rev. X · 2015 · 5 · 11029
6. 10.1038/ncomms837310.1038/ncomms8373 ↗
7. Lv B. Q. · Phys. Rev. X · 2015 · 5 · 31013
8. 10.1126/science.aaa929710.1126/science.aaa9297 ↗
9. 10.1038/nphys342610.1038/nphys3426 ↗
10. 10.1073/pnas.171326111410.1073/pnas.1713261114 ↗
11. 10.1038/nphys383910.1038/nphys3839 ↗
12. S.Ok M.Legner T.Neupert A. M.Cook arXiv:1703.03804v4 [cond‐mat.str‐el] 2017.
13. 10.1103/PhysRevLett.121.10640410.1103/PhysRevLett.121.106404 ↗
14. 10.1103/PhysRevB.98.20111610.1103/PhysRevB.98.201116 ↗
15. 10.1126/science.118992410.1126/science.1189924 ↗
16. 10.1103/PhysRevB.81.24520910.1103/PhysRevB.81.245209 ↗
17. 10.1126/sciadv.aaw568510.1126/sciadv.aaw5685 ↗
18. 10.1103/PhysRevLett.122.20640110.1103/PhysRevLett.122.206401 ↗
19. Hao Y.‐J. · Phys. Rev. X · 2019 · 9 · 41038
20. Li H. · Phys. Rev. X · 2019 · 9 · 41039
21. Chen Y. J. · Phys. Rev. X · 2019 · 9 · 41040
22. 10.1103/PhysRevB.97.21442210.1103/PhysRevB.97.214422 ↗
23. 10.1103/PhysRevB.94.04511210.1103/PhysRevB.94.045112 ↗
24. 10.1002/zaac.20110017910.1002/zaac.201100179 ↗
25. 10.1103/PhysRevLett.122.25640210.1103/PhysRevLett.122.256402 ↗
26. 10.1126/sciadv.aat034610.1126/sciadv.aat0346 ↗
27. 10.1126/sciadv.aaw471810.1126/sciadv.aaw4718 ↗
28. Ashcroft N. W. · 1976 · 702
29. 10.1103/PhysRevB.88.17442010.1103/PhysRevB.88.174420 ↗
30. 10.1088/1367-2630/11/2/02500710.1088/1367-2630/11/2/025007 ↗
31. 10.1103/PhysRevLett.95.14680210.1103/PhysRevLett.95.146802 ↗
32. 10.1103/PhysRevLett.98.10680310.1103/PhysRevLett.98.106803 ↗
33. 10.1038/s41467-017-00133-210.1038/s41467-017-00133-2 ↗
34. Khalaf E. · Phys. Rev. X · 2018 · 8 · 31070
35. 10.1103/PhysRevB.97.20513610.1103/PhysRevB.97.205136 ↗
36. 10.1209/0295-5075/81/5700610.1209/0295-5075/81/57006 ↗
37. 10.1038/ncomms113110.1038/ncomms1131 ↗
38. 10.1103/PhysRevB.92.22443510.1103/PhysRevB.92.224435 ↗
39. 10.1103/PhysRevB.92.12110910.1103/PhysRevB.92.121109 ↗
40. 10.1103/PhysRevB.92.24110310.1103/PhysRevB.92.241103 ↗
41. 10.1088/1361-648X/aa893210.1088/1361-648X/aa8932 ↗
42. 10.1073/pnas.171585111510.1073/pnas.1715851115 ↗
43. Z.Lin C.Wang P.Wang S.Yi L.Li Q.Zhang Y.Wang Z.Wang Y.Sun Z.Sun J.‐H.Cho C.Zeng Z.Zhang arXiv:1906.05755[cond‐mat.mtrl‐sci] 2019.
44. 10.1103/PhysRevLett.107.12640210.1103/PhysRevLett.107.126402 ↗
45. 10.1063/1.364646810.1063/1.3646468 ↗
46. 10.1016/0927-0256(96)00008-010.1016/0927-0256(96)00008-0 ↗
47. 10.1103/PhysRevB.54.1116910.1103/PhysRevB.54.11169 ↗
48. 10.1103/PhysRevLett.77.386510.1103/PhysRevLett.77.3865 ↗