Crystallographic defects in Weyl semimetal LaAlGe

Abstract

Crystallographic defects in a topological semimetal can result in charge doping, and the scattering due to the defects may mask its exotic transport properties. Here, we investigate the possible crystallographic defects including vacancy and antisite in Weyl semimetal LaAlGe using hybrid-density-functional theory calculations. We show that a considerable concentration of Al- and Ge-related defects naturally form during growth due to their low formation enthalpy. Specifically, Al can be easily replaced by Ge in the $I{4}_{1}md$ phase of LaAlGe, forming the Ge-on-Al antisite, Ge${}_{\mathrm{Al}}$. The counterpart, Al-on-Ge (Al${}_{\mathrm{Ge}}$), is also probable. The most abundant defect Ge${}_{\mathrm{Al}}$ is donor-like, effectively electron-doping, and these defects are therefore not only scattering centers in the electronic transport process but may also induce the substantial vertical shift of the chemical potential. The results imply that the naturally occurring defects hinder both spectroscopic and transport features arising from the Weyl physics in LaAlGe. Our work can be applied to the $R$AlGe family ($R$=rare earth) and help improve the quality of single-crystal magnetic Weyl semimetal.

References in corpus (18)

• Topological Insulators
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Discovery of a Weyl Fermion Semimetal and Topological Fermi Arcs
• Experimental discovery of Weyl semimetal TaAs
• First-Principles Calculations of Luminescence Spectrum Line Shapes for Defects in Semiconductors: The Example of GaN and ZnO
• Light control with Weyl semimetals
• Beyond Triplet: Unconventional Superconductivity in a Spin-3/2 Topological Semimetal
• Review of experiments on the chiral anomaly in Dirac-Weyl semimetals
• Dirac and Weyl Materials: Fundamental Aspects and Some Spintronics Applications
• Electronic structure of Pu and Am metals by self consistent relativistic GW
• Single crystal investigation of proposed type-II Weyl semimetal CeAlGe
• Current-Voltage Characteristics of Weyl Semimetal Semiconducting Devices, Veselago Lenses and Hyperbolic Dirac Phase
• Klein tunneling in Weyl semimetals under the influence of magnetic field
• Linearized self-consistent quasiparticle GW method: Application to semiconductors and simple metals
• ComDMFT: a Massively Parallel Computer Package for the Electronic Structure of Correlated-Electron Systems
• Breakdown of the scaling relation of anomalous Hall effect in Kondo lattice ferromagnet USbTe
• QSGW+DMFT: an electronic structure scheme for the iron pnictides and beyond
• High Fermi velocities and small cyclotron masses in LaAlGe

Cited by in corpus (1)

• Structural characterization of the candidate Weyl semimetal CeGaGe