通过钴/铂界面处的应变调节斯格明子的尺寸。

Tuning the size of skyrmion by strain at the Co/Pt interfaces.

作者信息

Jiang Lingzi, Huang Can, Zhu Yan, Pan Yanfei, Fan Jiyu, Zhang Kaicheng, Ma Chunlan, Shi Daning, Zhang Hongbin

机构信息

Department of Physics, College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210006, China.

MIIT Key Laboratory of Aerospace Information Materials and Physics, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China.

出版信息

iScience. 2022 Mar 7;25(4):104039. doi: 10.1016/j.isci.2022.104039. eCollection 2022 Apr 15.

DOI:10.1016/j.isci.2022.104039

PMID:35330683

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8938285/

Abstract

Based on density functional theory calculations, we elucidated the tunability of the atomic structures and magnetic interactions of Co/Pt interface (one layer of hcp(0001) Co and three layers of fcc(111) Pt) and thus the skyrmion sizes using strain. The dispersion relations of the spin spiral in the opposite directions, E() and E(-), were evaluated based on generalized Bloch equations. Effective exchange coupling (EC) and Dzyaloshinsky-Moriya interaction (DMI) parameters between different neighbors and at different lattice constants were derived by fitting the resulting spin spiral dispersion E() to EC model with DMI and E()-E(-) formula, respectively. We observed an increase in DMI and a significant decrease in EC with an increase in strain. Hence, the size of Néel-type skyrmions determined by the ratio of EC/DMI can be controlled by applying strain, leading to an effective approach to tailor the formation of skyrmion lattices by inducing slight structural modifications on the magnetic thin films.

摘要

基于密度泛函理论计算，我们阐明了Co/Pt界面（一层hcp(0001) Co和三层fcc(111) Pt）的原子结构和磁相互作用的可调性，进而利用应变调控了斯格明子尺寸。基于广义布洛赫方程评估了自旋螺旋在相反方向上的色散关系E(ω)和E(−ω)。通过分别将所得自旋螺旋色散E(ω)拟合到具有DMI的有效交换耦合（EC）模型和E(ω) - E(−ω)公式，推导出不同晶格常数下不同近邻之间的有效交换耦合（EC）和Dzyaloshinsky-Moriya相互作用（DMI）参数。我们观察到，随着应变增加，DMI增大而EC显著减小。因此，由EC/DMI比值决定的奈尔型斯格明子尺寸可通过施加应变来控制，这为通过在磁性薄膜上引入轻微结构修饰来定制斯格明子晶格的形成提供了一种有效方法。