Weyl points in the ferromagnetic Heusler compound Co₂MnAl

¹ Institut für Festkörperphysik, Technische Universität Darmstadt - D-64289 Darmstadt, Germany
² Max Planck Institute for Chemical Physics of Solids - D-01187 Dresden, Germany

Received: 25 May 2016
Accepted: 30 May 2016

Abstract

The anomalous Hall conductivity (AHC) in some ferromagnetic and antiferromagnetic Heusler compounds was theoretically and experimentally found to be exceptionally large. For the case of ferromagnetic Co₂MnAl we here argue that the large AHC is connected with the appearance of Weyl points near the Fermi energy. We find four Weyl points slightly above the Fermi edge. We describe our analysis for a magnetization being in the (110)-direction. For the possible (100)-direction we find at least four Weyl points, too. We predict that Co₂MnGa also possesses Weyl points near or at the Fermi energy.