First-principles evaluation of four-fold symmetric component of anisotropic magnetoresistance in 3d transition metal alloys

Anisotropic magnetoresistance (AMR) is a conventional magnetotransport phenomenon, and its origin is understood based on the Campbell-Fert-Jaoul model. Recent experimental studies of AMR reported that the four-fold symmetric component of the electrical resistivity is not so small compared to the two-fold symmetric component in several material films. Theoretically, Kokado and Tsunoda proposed that the four-fold symmetric component of AMR is attributed to the degradation of the crystalline symmetry due to tetragonal distortion [1], whereas Yahagi, Miura, and Sakuma proposed that the four-fold symmetric component arises from the higher order contribution of spin-orbit interaction [2]. The both proposed mechanisms are possible, however, it is unclear which mechanism is more important to generate the four-fold symmetric component of AMR in a realistic material system. In this study, we simulate the magnetization angle dependence of the electrical resistivity in ferromagnets using first-principles calculations. We present the comparison of the two- and four-fold symmetric component of AMR in cubic and tetragonally distorted crystals.
[1] S. Kokado and M. Tsunoda, J. Phys. Soc. Jpn. 84, 094710 (2015).
[2] Y. Yahagi, D. Miura, and A. Sakuma, arXiv:1905.01424 (2019).