Quaternary Heusler Alloy: An Ideal Platform to Realize Triple Point Fermion

TL;DR

This paper predicts quaternary Heusler alloys as ideal platforms for triply degenerate nodal points (TP), with robust topological Fermi arcs observable via spectroscopy, offering a promising route for studying triple point fermions.

Contribution

The study introduces specific quaternary Heusler alloys hosting stable triply degenerate nodal points, expanding the material candidates for triple point fermion research.

Findings

Identification of Heusler alloys with TP in their band structure.

Projection of TPs forms detectable topological Fermi arcs.

TPs are located away from the $ ext{Γ}$ point, easing experimental detection.

Abstract

The existence of three fold rotational, mirror and time reversal symmetries often give rise to the triply degenerate nodal point (TP) in the band structure of a material. Based on point group symmetry analysis and first principle electronic structure, we predict, in this article, a series of quaternary Heusler alloys host an ideal platform for the occurrence of TP. We simulated, the projection of these TPs onto the (111) and (100) surfaces lead to form topological Fermi arcs, which may further be detected by scanning tunneling spectroscopy and angle resolved photoemission spectroscopy. These Fermi arcs arise due to the symmetry protected band degeneracies, which are robust and can not be avoided due to the non-trivial band topology. Interestingly the TPs, in these class of Heusler alloys are far away from the $\Gamma$ point along C$_3$ axes, which allow to overcome the experimental difficulties over previously studied hexagonal and HgTe-type compounds.