Skip to main content
Article
Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2
Ames Laboratory Accepted Manuscripts
  • Lin-Lin Wang, Ames Laboratory
  • Na Hyun Jo, Iowa State University
  • Brinda Kuthanazhi, Iowa State University
  • Yun Wu, Iowa State University
  • Robert J. McQueeney, Iowa State University and Ames Laboratory
  • Adam Kaminski, Iowa State University and Ames Laboratory
  • Paul C. Canfield, Iowa State University and Ames Laboratory
Publication Date
6-26-2019
Department
Ames Laboratory; Physics and Astronomy
OSTI ID+
1542945
Report Number
IS-J 9874
DOI
10.1103/PhysRevB.99.245147
Journal Title
Physical Review B
Abstract

Materials with the ideal case of a single pair of Weyl points (WPs) are highly desirable for elucidating the unique properties of Weyl fermions. EuC d 2 A s 2 is an antiferromagnetic topological insulator or Dirac semimetal depending on the different magnetic configurations. Using first-principles band-structure calculations, we show that inducing ferromagnetism in EuC d 2 A s 2 can generate a single pair of WPs from splitting the single pair of antiferromagnetic Dirac points due to its half-metallic nature. Analysis with a low-energy effective Hamiltonian shows that a single pair of WPs is obtained in EuC d 2 A s 2 because the Dirac points are very close to the zone center and the ferromagnetic exchange splitting is large enough to push one pair of WPs to merge and annihilate at Γ while the other pair survives. Furthermore, we predict that alloying with Ba at the Eu site can stabilize the ferromagnetic configuration and generate a single pair of Weyl points without application of a magnetic field.

DOE Contract Number(s)
AC02-07CH11358
Language
en
Publisher
Iowa State University Digital Repository, Ames IA (United States)
Citation Information
Lin-Lin Wang, Na Hyun Jo, Brinda Kuthanazhi, Yun Wu, et al.. "Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2" Vol. 99 Iss. 24 (2019) p. 245147
Available at: http://works.bepress.com/paul_canfield/196/