Theoretical Study on Four-fold Symmetric Anisotropic Magnetoresistance Effect in Cubic Single-crystal Ferromagnetic Model
Abstract
Our study is a theoretical investigation aimed at deriving a possible mechanism for the four-fold symmetric term (c4) of the anisotropic magnetoresistance (AMR) effect in cubic ferromagnets, which has recently been observed experimentally for certain transition metals. We employ a model based on the Anderson impurity model, which includes a cubic crystalline electric field, and we assume that the impurities have 3d electron orbitals and undergo spin-orbit interactions (SOIs). We describe the DC conductivity on the basis of the Kubo formula, and we investigate c4 by analyzing the extent to which the resultant AMR ratio depends on the direction of magnetization. Analytical and numerical calculations were conducted, with the former revealing that c4 arises from the fourth-order contribution of the SOI, and the latter providing the parameter dependencies of c4. Our results indicate that the splitting of the 3d levels of the impurities owing to SOI is responsible for the c4 in cubic ferromagnetic metals.
- Publication:
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Journal of the Physical Society of Japan
- Pub Date:
- April 2020
- DOI:
- 10.7566/JPSJ.89.044714
- arXiv:
- arXiv:1905.01424
- Bibcode:
- 2020JPSJ...89d4714Y
- Keywords:
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- Physics - Applied Physics;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 15 pages, 7 figures