蒙特卡罗模拟人工自旋冰的退磁过程  

Monte Carlo simulation on demagnetization of artificial spin ice

作　　者：虞丽菊 孟祥雨[2] 李俊琴[2] 曹杰峰[2] 王勇[2] 敬超[1] 吴衍青[2] 邰仁忠[2] 

机构地区：[1]上海大学物理系 [2]中国科学院上海应用物理研究所张江园区

出　　处：《核技术》2016年第6期71-76,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.11475251;No.11275255;No.11225527;No.5137111);上海市科委基础研究重点项目(No.13JC402400)资助~~

摘　　要：近年来,人工自旋冰(Artificial spin ice,ASI)因具有潜在的应用价值以及理论研究价值而倍受关注,成为磁学领域的研究热点之一。以往的研究集中在Square和Kagome两种晶格结构,由于能量势垒和阻挫的大量存在,实验上难以通过退磁等方法达到其内部相互作用决定的能量基态。本文基于Kagome晶格结构提出了一种新的人工自旋冰结构,并基于蒙特卡罗模拟了三种不同的退磁方法对体系能量的影响。结果表明,退磁过程中旋转磁场方向可更有效地降低体系能量,并诱导多种磁结构的出现。Background Recently, the artificial spin ice （ASI） draws a wide attention for its exotic phenomenon andpotential applications. Previous works mainly studied the Square and Kagome lattice systems, and extensiveresearches concentrated upon how to achieve the ground state. It turned out to be experimentally difficult to get theabsolute ground state of Kagome ASI because of the high frustration. Purpose： Here we propose a new structurebased on Kagome lattice, which is just locally frustrated. In order to get good approximation of its ground state, weemployed a Monte Carlo simulation on demagnetization process with three methods. Methods： The Monte Carlosimulation was carried on a system including 21×21 cells, and an extra field had been employed to drive the spinsoverturning. Results ＆ Conclusion： It turned out that the rotating magnetic field was more effective to get to theground state, and induced the emergence of various magnetic structures.

关 键 词：人工自旋冰 蒙特卡罗模拟 退磁 

分 类 号：TL65[核科学技术—核技术及应用]