Unraveling atomistic and electronic origins of multiaxial magnetic anisotropy  

作　　者：Boyu Liu Xueyang Li Junsheng Feng Changsong Xu Hongjun Xiang 

机构地区：[1]Key Laboratory of Computational Physical Sciences(Ministry of Education),Institute of Computational Physical Sciences,State Key Laboratory of Surface Physics and Department of Physics,Fudan University,Shanghai,200433,China [2]Shanghai Qi Zhi Institute,Shanghai,200030,China [3]School of Physics and Material Engineering,Hefei Normal University,Hefei,230601,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2025年第2期175-182,共8页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Key R&D Program of China(Grant No.2022YFA1402901);National Natural Science Foundation of China(Grant Nos.11825403,11991061,12188101,12174060,and 12274082);the Guangdong Major Project of the Basic and Applied Basic Research(Grant No.2021B0301030005);Shanghai Pilot Program for Basic Research—FuDan University 21TQ1400100(Grant No.23TQ017);support from the Shanghai Science and Technology Committee(Grant No.23ZR1406600);support from the Scientific Research Project of Universities in Anhui Province(Grant No.2024AH040216)。

摘　　要：Multiaxial magnetic anisotropy(MA)refers to the phenomenon that multiple axes of the magnetic crystal correspond to different energy minima.Compared with the common uniaxial magnetic anisotropy,multiaxial MA facilitates novel forms of applications in spintronics.Here,by combining the first-principles-based spin Hamiltonian and tight-binding(TB)method,we reveal the microscopic origins,instead of the common phenomenological understanding,of biaxial MA and triaxial MA.In the example system of NiO,it is found that the multiple minima result from the fourth-order and the sixth-order single ion interactions,while the difference between[110]and[110]directions originates from a second-order bond-dependent anisotropic pair interaction(i.e.,the so-called Gamma interaction).Moreover,through the application of a newly developed general spin dependent TB approach,it is revealed that the triaxial MA arises from the special spin-orbital entangled Hund term,which is different from the orbital-independent Hund term in the usual Slater Koster TB method.Our work thus not only leads to a thorough understanding of the multiaxial MA in NiO,but also establishes a methodology that can be widely used to explore the microscopic origins of MA in different magnets.

关 键 词：multiaxial magnetic anisotropy origin of multiaxial magnetic mnisotropy effective spin Hamiltonian tight-binding model ANTIFERROMAGNETISM 

分 类 号：O469[理学—凝聚态物理]