A Single Pair of Weyl Fermions in Half-metallic EuCd2As2 Semimetal

Abstract

An ideal Weyl semimetal with a single pair of Weyl points (WPs) may be generated by splitting a single Dirac point (DP) through the breaking of time-reversal symmetry by magnetic order. However, most known Dirac semimetals possess a pair of DPs along an axis that is protected by crystalline symmetry. Here, we demonstrate that a single pair of WPs may also be generated from a pair of DPs. Using first-principles band structure calculations, we show that inducing ferromagnetism in the AFM Dirac semimetal EuCd2As2 generates a single pair of WPs due to its half-metallic nature. Analysis with a low-energy effective Hamiltonian shows that this ideal Weyl semimetal is obtained in EuCd2As2 because the DPs 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 Gamma 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.

21 pages, 5 figures

References in corpus (4)

• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Classification of stable three-dimensional Dirac semimetals with nontrivial topology
• Antiferromagnetic topological insulators
• Anomalous Hall Effect in Weyl Metals

Cited by in corpus (58)

• Progress and prospects in magnetic topological materials
• Ab-initio overestimation of the topological region in Eu-based compounds
• Single Pair of Weyl Points in Nonmagnetic Crystals
• Anisotropy of the magnetic and transport properties in EuZn${}_2$As${}_2$
• Pressure-induced ferromagnetism in the topological semimetal EuCd${}_2$As${}_2$
• Recipe for single-pair-Weyl-points phonons carrying the same chiral charges
• Colossal magnetoresistance in EuZn${}_2$P${}_2$ and its electronic and magnetic structure
• Consecutive topological phase transitions and colossal magnetoresistance in a magnetic topological semimetal
• Single pair of Weyl nodes in the spin-canted structure of EuCd${}_2$As${}_2$
• Intrinsic Magnetic Topological Materials
• Resonant X-ray scattering study of diffuse magnetic scattering from the topological semimetals EuCd${}_2$As${}_2$ and EuCd${}_2$Sb${}_2$
• Spin-carrier coupling induced ferromagnetism and giant resistivity peak in EuCd${}_2$P${}_2$
• Topological Hall Effect Driven by Short-Range Magnetic Orders in EuZn${}_2$As${}_2$
• A-type antiferromagnetic order in semiconducting EuMg${}_2$Sb${}_2$ single crystals
• The discovery of three-dimensional Van Hove singularity
• Realization of the Single-pair-Weyl Phonons with the Maximum Charge Number in Acoustic Crystals
• The magnetic structure of the topological semimetal Co${}_3$Sn${}_2$S${}_2$
• Optical properties and carrier localization in the layered phosphide EuCd${}_2$P${}_2$
• Evidence of Ba substitution induced spin-canting in the magnetic Weyl semimetal EuCd${}_2$As${}_2$
• Engineering the in-plane anomalous Hall effect in Cd${}_3$As${}_2$ thin films
• Magnetic and electronic structure of the topological semimetal YbMnSb${}_2$
• Giant and Reversible Electronic Structure Evolution in a Magnetic Topological Material EuCd2As2
• Magneto-optical Kerr effect in Weyl semimetals with broken inversion and time-reversal symmetries
• Carrier-induced transition from antiferromagnetic insulator to ferromagnetic metal in the layered phosphide EuZn${}_2$P${}_2$
• Visualizing band selective enhancement of quasiparticle lifetime in a metallic ferromagnet
• Large nonsaturating magnetoresistance, weak anti-localization and non-trivial topological states in SrAl${}_2$Si${}_2$
• Manipulating magnetism and transport properties of EuCd${}_2$P${}_2$ with a low carrier concentration
• Absence of Weyl nodes in EuCd${}_2$As${}_2$ revealed by the carrier density dependence of the anomalous Hall effect
• Symmetry-breaking pathway towards the unpinned broken helix
• Axions and Superfluidity in Weyl Semimetals
• Intrinsic ferromagnetic axion states and a single pair of Weyl fermions in the stable-state Mn\emph{X}${}_2$\emph{B}${}_2$\emph{T}${}_6$-family materials
• Anomalous Electromagnetic Field Penetration in a Weyl or Dirac Semimetal
• Intrinsic insulating transport characteristics in low-carrier density EuCd2As2 films
• Long-Time Magnetic Relaxation in Antiferromagnetic Topological Material EuCd${}_2$As${}_2$
• Pressure-induced ideal Weyl semimetal state in the layered antiferromagnet EuCd2As2
• Berry curvature derived negative magnetoconductivity observed in type-II magnetic Weyl semimetal films
• Pressure Effect on Band Inversion in AECd2As2
• Unusual magnetic and transport properties in the Zintl phase Eu${}_{11}$Zn${}_6$As${}_{12}$
• Influence of magnetism, strain and pressure on the band topology of EuCd${}_2$As${}_2$
• Absence of metallicity and bias-dependent resistivity in low-carrier-density EuCd2As2
• Anomalous Gurzhi effect
• Flavors of Magnetic Noise in Quantum Materials
• Recent advances in understanding and manipulating magnetic and electronic properties of Eu$M_2{X}_2$ ($M$ = Zn, Cd; $X$ = P, As)
• Stark difference in the in-plane anomalous Hall response in Zintl compounds EuA2Sb2 (A = Zn, Cd) thin films
• Nonreciprocal Weyl semimetal waveguide
• Topological Descendants of Multicritical EuTl2
• Observation of paramagnetic spin-degeneracy lifting in EuZn2Sb2
• Observation of multiple Dirac states in a magnetic topological material EuMg2Bi2
• Interplay of magnetism and band topology in Eu${}_{1-x}$Ca${}_x$Mg${}_2$Bi${}_2$ (x=0, 0.5) from first principles study
• Incommensurate magnetic order in an axion insulator candidate EuIn${}_2$As${}_2$ investigated by NMR measurement
• Doping Topological Dirac Semimetal with magnetic impurities: electronic structure of Mn-doped Cd${}_3$As${}_2$
• Spectroscopic signatures of magnetization-induced band renormalization and strong spin-charge-lattice coupling in EuZn${}_2$As${}_2$
• Electric and chiral response to a pseudoelectric field in Weyl materials
• Absence of superconductivity in topological metal ScInAu${}_2$
• Effective Tight-Binding Model of Compensated Ferrimagnetic Weyl Semimetal with Spontaneous Orbital Magnetization
• Structural design and multiple magnetic orderings of the intergrowth compound Eu${}_2$CuMn${}_2$P${}_3$
• Design, synthesis, and physical properties of the intergrowth compound Eu${}_2$CuZn${}_2$As${}_3$
• Ferroelectrically Controlled Chirality Switching of Weyl Quasiparticles