Co-existence of Weyl Fermion and Massless Triply Degenerate Nodal Points

TL;DR

This paper predicts that ZrTe, a topological semimetal, hosts both Weyl fermions and triply degenerate nodal points, revealing a new class of materials supporting multiple exotic particles.

Contribution

It introduces ZrTe as a novel topological semimetal hosting both Weyl fermions and triply degenerate nodal points, expanding the understanding of topological materials.

Findings

ZrTe has six pairs of Weyl nodes with same energy and velocity.

Presence of triply degenerate nodal points in ZrTe.

Fermi arcs predicted on different surfaces for experimental verification.

Abstract

By using first-principles calculations, we propose that WC-type ZrTe is a new type of topological semimetal (TSM). It has six pairs of chiral Weyl nodes in its first Brillouin zone, but it is distinguished from other existing TSMs by having additional two paris of massless fermions with triply degenerate nodal points as proposed in the isostructural compounds TaN and NbN. The mirror symmetry, three-fold rotational symmetry and time-reversal symmetry require all of the Weyl nodes to have the same velocity vectors and locate at the same energy level. The Fermi arcs on different surfaces are shown, which may be measured by future experiments. It demonstrates that the "material universe" can support more intriguing particles simultaneously.