Magnetic Weyl Semimetals

Topology a mathematical concept became recently a hot topic in condensed matter physics and materials science. One important criteria for the identification of the topological material is in the language of chemistry the inert pair effect of the s-electrons in heavy elements and the symmetry of the crystal structure [1]. Beside of Weyl and Dirac new fermions can be identified compounds via linear and quadratic 3-, 6- and 8- band crossings stabilized by space group symmetries [2]. In magnetic materials the Berry curvature and the classical AHE helps to identify interesting candidates. Magnetic Heusler compounds were already identified as Weyl semimetals such as Co₂YZ [3-6] (Y=Ti, Mn; Z=Ge, Sn, Ga, Al), in Mn₃Z [7-9] (Z=Ge, Sn). Co₃Sn₂S₂ is a 2D Weyl semimetal with edge states [11-12].

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