Weyl semimetal engineering by symmetry control in NiTe2

Abstract

In this work, we investigate the emergence of Weyl points in an inversion symmetry-breaking 1T-NiTe2 system. Through first-principles calculations based on the density functional theory combined with tight-binding methods, we find three distinct sets of Weyl crossings under an appropriate symmetry breaking. The first set, composed of four Weyl points, emerges from the Dirac semimetal. Surprisingly, the other two sets result in additional 24 Weyl crossings, depending on the weight of the symmetry breaking. We investigate the topological characteristics of the Weyl semimetals by computing the Weyl chirality, Berry curvature, and the evolution of Wannier charge centers. Additionally, the bulk-boundary correspondence has been shown by computing the Fermi arcs. Our results provide a way for creating and manipulating distinct sets of Weyl points with appropriate external control, which can provide a valuable guide to design Weyl crossings in materials for applications in the Weyltronics field.