A Theory for Anisotropic Magnetoresistance in Materials with Two Vector Order Parameters  

作　　者：X.R.Wang 王向荣(Department of Physics,The Hong Kong University of Science and Technology,Hong Kong,China;HKUST Shenzhen Research Institute,Shenzhen 518057,China)

机构地区：[1]Department of Physics,The Hong Kong University of Science and Technology,Hong Kong,China [2]HKUST Shenzhen Research Institute,Shenzhen 518057,China

出　　处：《Chinese Physics Letters》2022年第2期59-63,共5页中国物理快报（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant Nos.2020YFA0309600 and 2018YFB0407600);the National Natural Science Foundation of China(Grant Nos.11974296 and 11774296);Hong Kong RGC(Grant Nos.16301518,16301619,and 16302321)。

摘　　要：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 π/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 π/4.Instead ofπperiodicity of the usual AMR and PHR,the periodicities of materials with two order parameters are 2π.

关 键 词：MATERIALS RESISTANCE reversed 

分 类 号：O469[理学—凝聚态物理]