skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on June 15, 2020

Title: Single pair of Weyl fermions in the half-metallic semimetal EuC d 2 A s 2 [A Single Pair of Weyl Fermions in Half-metallic EuCd 2As 2 Semimetal]

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. EuCd 2As 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 EuCd 2As 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 EuCd 2As 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. As a result, 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.

Authors:
 [1];  [2];  [2];  [2];  [3];  [3];  [3]
  1. Ames Lab., Ames, IA (United States)
  2. Iowa State Univ., Ames, IA (United States)
  3. Ames Lab. and Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1542945
Alternate Identifier(s):
OSTI ID: 1546278
Report Number(s):
IS-J-9874
Journal ID: ISSN 2469-9950; PRBMDO
Grant/Contract Number:  
AC02-07CH11358
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 99; Journal Issue: 24; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Wang, Lin -Lin, Jo, Na Hyun, Kuthanazhi, Brinda, Wu, Yun, McQueeney, Robert J., Kaminski, Adam, and Canfield, Paul C. Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2 [A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal]. United States: N. p., 2019. Web. doi:10.1103/PhysRevB.99.245147.
Wang, Lin -Lin, Jo, Na Hyun, Kuthanazhi, Brinda, Wu, Yun, McQueeney, Robert J., Kaminski, Adam, & Canfield, Paul C. Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2 [A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal]. United States. doi:10.1103/PhysRevB.99.245147.
Wang, Lin -Lin, Jo, Na Hyun, Kuthanazhi, Brinda, Wu, Yun, McQueeney, Robert J., Kaminski, Adam, and Canfield, Paul C. Sat . "Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2 [A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal]". United States. doi:10.1103/PhysRevB.99.245147.
@article{osti_1542945,
title = {Single pair of Weyl fermions in the half-metallic semimetal EuCd2As2 [A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal]},
author = {Wang, Lin -Lin and Jo, Na Hyun and Kuthanazhi, Brinda and Wu, Yun and McQueeney, Robert J. and Kaminski, Adam and Canfield, Paul C.},
abstractNote = {Materials with the ideal case of a single pair of Weyl points (WPs) are highly desirable for elucidating the unique properties of Weyl fermions. EuCd2As2 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 EuCd2As2 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 EuCd2As2 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. As a result, 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.},
doi = {10.1103/PhysRevB.99.245147},
journal = {Physical Review B},
number = 24,
volume = 99,
place = {United States},
year = {2019},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 15, 2020
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

Projector augmented-wave method
journal, December 1994


Self-Consistent Equations Including Exchange and Correlation Effects
journal, November 1965


Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set
journal, July 1996


Special points for Brillouin-zone integrations
journal, June 1976

  • Monkhorst, Hendrik J.; Pack, James D.
  • Physical Review B, Vol. 13, Issue 12, p. 5188-5192
  • DOI: 10.1103/PhysRevB.13.5188

Colloquium: Topological insulators
journal, November 2010


Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996


Inhomogeneous Electron Gas
journal, November 1964