几何阻挫磁系统的磁序态和"磁单极"研究

项目名称： 几何阻挫磁系统的磁序态和"磁单极"研究

项目编号： No.11204064

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 物理学I

项目作者： 李英

作者单位： 河北工业大学

项目金额： 20万元

中文摘要： 自旋冰态和准粒子"磁单极"是近年来被发现在几何阻挫磁系统烧绿石结构化合物中的磁现象，这些发现为探索自然界中基本的物理现象提供了良好的基础。本课题利用第一性原理结合蒙特卡罗模拟方法，对几何阻挫磁系统的磁基态序和"磁单极"现象进行基础研究。具体内容包括:（1）阻挫多铁性材料ABO3 和AB2O5(A=稀土元素，B=3d过渡元素)的基态磁序相，以及磁离子间相互作用和 Dzyaloshinskii-Moriya 作用对系统磁序相的影响；(2) 在掺杂导致的成分变化或晶格应力、外场和温度等因素影响下，阻挫系统ABO3 和AB2O5的磁相变情况；（3）人工几何阻挫磁晶格在外磁场下的磁化强度反转性质，探讨人工磁晶格中磁荷序和"磁单极"产生的机制和产生的系统的拓扑结构特征。本项目研究在揭示几何阻挫磁系统的磁性本征行为和基本的物质属性方面有重要的科学意义。

中文关键词： 阻挫作用；稀土锰氧化物；磁基态；人工自旋冰；磁荷序

英文摘要： The spin ice state and "magnetic monopole" were recently found in the geometrically frustrated pyrochlore oxides. These findings pave the way to a study of the basic physical phenomena in nature. In this project, we will study the frustrated magnetic ground state and "magnetic monopole" of geometrically frustrated systems with density functional theory together with Monte Carlo simulations. The main contents include: (1)the magnetic order phases of geometricall frustrated multiferroics ABO3 and AB2O5( A = rare earth ions, B = 3d transitional metal ions), and the effect of 3d-4f interactions, the long-range dipolar interactions between rare-earth ions, and Dzyaloshinskii-Moriya interactions on the magnetic order phases; (2) the magnetic order phases of ABO3 and AB2O5 confined in the external forces such as dopant, crystal stress, the magnetic field, and the temperature, and so on; (3) the magnetization reversal properites of artifical frustrated magnets in the presence of magnetic field, and a possible topological structure where the magnetic charger ordering and the emergent particle "magnetic monopole" can occur. The project is of great importance for revealing the intrinsic magnetism of geometrically frustrated systems.

英文关键词： frustrated interaction；rare earth mangnanese oxides；magnetic ground state；artificial spin ice；magnetic charge order