Alloy engineering of topological semimetal phase transition in MgTa${}_{2-x}$Nb${}_x$N${}_3$

Abstract

Dirac, triple-point and Weyl fermions represent three topological semimetal phases, characterized with a descending degree of band degeneracy, which have been realized separately in specific crystalline materials with different lattice symmetries. Here we demonstrate an alloy engineering approach to realize all three types of fermions in one single material system of MgTa${}_{2-x}$Nb${}_x$N${}_3$. Based on symmetry analysis and first-principles calculations, we map out a phase diagram of topological order in the parameter space of alloy concentration and crystalline symmetry, where the intrinsic MgTa${}_2$N${}_3$ with the highest symmetry hosts the Dirac semimetal phase which transforms into the triple-point and then the Weyl semimetal phase with the increasing Nb concentration that lowers the crystalline symmetries. Therefore, alloy engineering affords a unique approach for experimental investigation of topological transitions of semimetallic phases manifesting different fermionic behaviors.

in press, Phys. Rev. Lett. (2018)

References in corpus (13)

• A topological Dirac insulator in a quantum spin Hall phase : Experimental observation of first strong topological insulator
• WannierTools: An open-source software package for novel topological materials
• Weyl semimetal phase in non-centrosymmetric transition metal monophosphides
• Computing topological invariants without inversion symmetry
• Discovery of a new type of topological Weyl fermion semimetal state in Mo${}_x$W${}_{1-x}$Te${}_2$
• Three-component fermions with surface Fermi arcs in topological semimetal tungsten carbide
• Prediction of triple point fermions in simple half-Heusler topological insulators
• Topological tuning in three-dimensional Dirac semimetals
• Dirac Fermion in Strongly-Bound Graphene Systems
• Coexistence of New Fermions in Topological Semimetal TaS
• Prediction of Ideal Topological Semimetals with Triply Degenerate Points in NaCu${}_3$Te${}_2$ Family
• Mirror protected Dirac fermions on a Weyl semimetal NbP surface
• High-pressure phases of Weyl semimetals NbP, NbAs, TaP and TaAs

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