Positron annihilation spectroscopy for the pure and Niobium doped ZrCo$_2$Sn Heusler compound

TL;DR

This study uses positron annihilation spectroscopy and density functional theory to investigate Weyl points in ZrCo$_2$Sn Heusler compounds, revealing the effects of Niobium doping on their electronic structure.

Contribution

It demonstrates the application of 2D-ACAR calculations combined with GGA+U to identify Weyl points in doped Heusler compounds, highlighting the impact of Nb doping.

Findings

Weyl points are confirmed near the Fermi level in Nb-doped ZrCo$_2$Sn.

Doping shifts Weyl points closer to the Fermi level.

Positron annihilation results suggest the presence of Weyl points, but with some uncertainty.

Abstract

We perform spin-polarized two-dimensional angular correlation of annihilation radiation (2D-ACAR) calculations for the recently predicted ZrCo$_2$Sn-Weyl Heusler compound within the density functional theory using the generalized gradient approximation (GGA) and its extension GGA+U. We confirm that within the GGA+U method, a pair of Weyl-points are revealed, and that by doping with Niobium, for the composition Nb$_{0.3}$Zr$_{0.7}$Co$_2$Sn, the Weyl points are reaching the Fermi level. Our 2D-ACAR results indicate the existence of the Weyl points, however, within the present calculation, it is uncertain if the smearing at the Fermi level can be attributed to the positron wave function.