Anisotropic magnetoresistance in Co₂MnGa thin films

The full Heusler compound Co₂MnGa belongs to the family of Weyl-II-semimetals. Large anomalous Nernst effect has been observed in Co2 MnGa [1] and it was attributed to non-vanishing Berry curvature close to the Weyl points making the material a promising candidate for study of exotic transport phenomena. In this work, I focus on the anisotropic magnetoresistance (AMR) in Co₂MnGa thin films. The AMR is measured in a series of samples of various thicknesses t at different temperatures T allowing for a quantitative study of the AMR parameters as a function of t, T. The data is modeled using a symmetry-based model [2,3] for the AMR and various contributions are identified. While the temperature-dependence of the parameters is as expected, the dependence on t remains less well explained. I will also show preliminary magneto-thermopower measurements and discuss further plans.

• [1] Akito Sakai et al., Nature Physics 14, 1119 (2018), doi:10.1038/s41567-018-0225-6
• [2] Edmund C Stoner and Erich P Wohlfarth, Philos. Trans. R. Soc. London A 240, 599 (1948), doi:10.1098/rsta.1948.0007.
• [3] Andrew W Rushforth et al., Phys. Rev. Lett. 99, 147207 (2007), doi:10.1103/PhysRevLett.99.147207.