Magnetic Weyl Semi-Metallicity and Berry Curvature-Driven Transport Signatures in CoYCrAl Quaternary Heusler Compound

Abstract

The anomalous electronic transport arising from the interplay between magnetism and band topology leads to remarkable phenomena such as the anomalous Hall and Nernst effects. In this study, we have computationally investigated the electronic, magnetic, topological, and anomalous transport properties of the CoYCrAl quaternary Heusler compound. The Spin-polarized calculation confirmed the half-metallic nature of this compound. A tight-binding approach based on Wannier functions, including spin-orbit coupling, is used to investigate the topological features, revealing multiple Weyl nodes with opposite chiralities. The presence of the symmetry-protected Fermi arc and topological surface states confirmed the material's Weyl semi-metallic nature. Further, we evaluate the Berry curvature corresponding to the electronic bandstructure along [001] crystallographic direction, under the effect of spin-orbit coupling. The Berry curvature-driven anomalous Hall conductivity is found to be 548.49 Scm⁻¹, which corresponds to a linear band crossing. Furthermore, a strong anomalous Nernst signal with a magnitude of −3.44 Am⁻¹K⁻¹ is observed at room temperature. These anomalous transport outcomes with topological characteristics highlight the potential of the CoYCrAl compound for spintronic and thermoelectric applications.