标题：
Dzyaloshinsky-Moriya interaction in delta-(Zn, Cr)S(111) surface: First principle calculations
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所属单位：
理学院
发表刊物：
ACTA PHYSICA SINICA
关键字：
first principles Dzyaloshinsky-Moriya interaction heterojunction skyrmion
摘要：
According to density functional theory calculations, we elucidate the atomic and electronic structure of delta-(Zn, Cr)S(111) surface. The magnetic interaction between Cr atoms is via S atoms close to the Cr layer. This interaction is shown by the analysis of spin charge contour plot and partial density of states (DOS) of each atom. The DOSs of other S atoms are non magnetic and have no magnetic exchange with the Cr layer. E(q) and E(-q) are the dispersions between energy E and wave vector q of spin spiral in the opposite directions. They are calculated with generalized Bloch equations and all the magnetic moments of Cr atoms are arranged in the plane perpendicular to the delta-(Zn, Cr)S(111) film The differences between E(q) and E(-q) are caused by the interface of delta-(Zn, Cr)S(111), where the symmetry of space perpendicular to the film is broken. Effective Heisenberg exchange interaction (HBI) and Dzyaloshinsky-Moriya interaction (DMI) parameters between different neighbors (J(i) and d(i)) are derived by well fitting the ab initio spin spiral dispersion E(q) to HBI with DMI model and E(q)-E(-q) to DMI model, respectively. The J(2) plays a major role with a large negative value of -9.04 meV. The J(1) is about 2/5 of J(2), and J(3) is about 1/4 of J(2) with positive value. The DMI d(1) is -0.53 meV, and d(2) is 0.07 meV. With these HBI parameters, E(0) is the largest one at which delta-(Zn, Cr)S(111) has no ferromagnetic interface. The E(q) has its lowest energy with the q at M = b(1)/2 in the first Brillouin zone. Hence, delta-(Zn, Cr)S(111) is an M-type antiferromagnetic (AFM) material. In this type of AFM configuration, magnetic moments of Cr atom in a line along b(2) are parallel to each other, and antiparallel to the magnetic moments in adjacent lines. The E(q) at K = b(1)/2 b(2)/2 is almost as large as that at Gamma point. The value of DMI parameter d(1) is about 1/5 of that on Co/Pt3 interface and 1/2 of Co/graphene. However, it is a negative number, which shows the clockwise chirality. The delta-(Zn, Cr)S(111) interface has obvious DMI, and skyrmion may be formed at this transition-metal/semiconductor (TM/S) interface. It is a good option to search for DMI in different kinds of TM/S heterojunctions. The material that combines the advantage of heterojunction, and DMI may have new magnetic phenomenon, which is usefulfor the magnetic storage. This paper enriches the research on DMI.
ISSN号：
1000-3290
是否译文：
否
发表时间：
2018-07-05
合写作者：
Li Xiao-Ying,Huang Can,李晋斌,樊济宇,潘燕飞,施大宁,Ma Chun-Lan
通讯作者：
朱岩,潘燕飞,朱岩
发表时间：
2018-07-05
学位：理学博士学位
职称：副教授
所在单位：理学院