A Theory for Anisotropic Magnetoresistance in Materials with Two Vector Order Parameters
X. R. Wang1,2*
1Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China 2HKUST Shenzhen Research Institute, Shenzhen 518057, China
Abstract：Anisotropic magnetoresistance (AMR) and related planar Hall resistance (PHR) are ubiquitous phenomena of magnetic materials. Although the universal angular dependences of AMR and PHR in magnetic polycrystalline materials with one order parameter are well known, no similar universal relation for other class of magnetic materials are known to date. Here a general theory of galvanomagnetic effects in magnetic materials is presented with two vector order parameters, such as magnetic single crystals with a dominated crystalline axis or polycrystalline non-collinear ferrimagnetic materials. It is shown that AMR and PHR have a universal angular dependence. In general, both longitudinal and transverse resistivity are non-reciprocal in the absence of inversion symmetry: Resistivity takes different values when the current is reversed. Different from simple magnetic polycrystalline materials where AMR and PHR have the same magnitude, and $\pi/4$ out of phase, the magnitudes of AMR and PHR of materials with two vector order parameters are not the same in general, and the phase difference is not $\pi/4$. Instead of $\pi$ periodicity of the usual AMR and PHR, the periodicities of materials with two order parameters are $2\pi$.
收稿日期: 2021-12-14
Express Letter
出版日期: 2022-01-06
引用本文:
. [J]. 中国物理快报, 2022, 39(2): 27301-027301.
X. R. Wang. A Theory for Anisotropic Magnetoresistance in Materials with Two Vector Order Parameters. Chin. Phys. Lett., 2022, 39(2): 27301-027301.
Nadvornik L, Borchert M, Brandt L, Schlitz R, de Mare K A, Vyborny K, Mertig I, Jakob G, Klaui M, Goennenwein S T B, Wolf M, Woltersdorf G, and Kampfrath T 2021 Phys. Rev. X11 021030
De Ranieri E, Rushforth A W, Vyborny K, Rana U, Ahmad E, Campion R P, Foxon C T, Gallagher B L, Irvine A C, Wunderlich J, and Jungwirth T 2008 New J. Phys.10 065003
2022, Vol. 39 
