二维复式晶格磁振子晶体的带隙结构  

Band-gap structures of two-dimensional magnonic crystals with complex lattices

作　　者：刘艳玲[1] 刘文静[1] 包佳美[1] 曹永军[1] 

机构地区：[1]内蒙古师范大学物理与电子信息学院,呼和浩特010022

出　　处：《物理学报》2016年第15期218-224,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11264028);内蒙古自治区自然科学基金(批准号:2015BS0106);内蒙古师范大学2015年度研究生创新基金(批准号:CXJJS15076)资助的课题~~

摘　　要：提出了一种复式晶格磁振子晶体的模型,该模型由两种铁磁材料散射体周期排列在另一种铁磁材料基底中构成.应用超原胞的思想拓展了平面波展开法,用于数值计算研究自旋波在复式晶格磁振子晶体中的本征性质本文数值计算了由两种大小不同的铁(Fe)-铁(Fe)圆柱体交替正方排列在氧化铕(EuO)基底材料中构成的二维复式晶格磁振子晶体的带结构,研究了带隙宽度随体积填充率的变化行为,并与同一铁(Fe)圆柱正方排列在氧化铕(EuO)基底材料中构成的简单晶格磁振子晶体的带隙结构随体积填充率的变化行为进行了比较.结果表明,利用复式晶格可以优化或调节自旋波带隙的宽度和频率位置.Magnonic crystals with spin waves as information carriers are the magnetic counterparts of photonic and phononic crystals.The studies of spin waves or magnons in magnonic crystals have attracted increasing attention,especially for the characteristics of band gaps.However,most of the previous work has paid attention to the magnonic crystals with simple lattices.In this paper,the model of magnonic crystals with complex lattices which is composed of two different scatterers of ferromagnetic materials periodically embedded in another kind of ferromagnetic matrix material is proposed for the first time.Then,the plane-wave expansion method is developed by using the idea of super cells,in which the Fourior coefficient of exchange constant αin the space of reciprocal lattice vector is analytically derived,and this method can be used to numerically investigate the eigen-properties of spin waves in magnonic crystals with complex lattices.Of course,it can be applied to the fields of other artificial crystals with complex lattices after the corresponding process,such as photonic crystals and phononic crystals.Band structures of two-dimensional magnonic crystal with complex lattices consisting of two different sizes of Fe cylinders alternately arranged in Euo matrix,are numerically calculated by using the above plane-wave expansion method.The behaviors of band gaps of spin waves changing with the total filling fraction of volume f and also with the mismatch of the filling fraction of volume of two Fe cylinders in EuO matrix are numerically studied.The results of magnonic crystals with complex lattices are compared with those of magnonic crystal with simple latticeic.Some conclusions are summarized as follows.In the same filling fraction of volume f,the width of band gap B4,5 in the magnonic crystal with complex lattice is always larger than that with the simple lattice,but the width of band gap B8,9in the complex lattice is less than that in the simple lattice.When f =（fA ＋fB）/2 = 0.5,the width of band gap B4,5increase

关 键 词：磁振子晶体 复式晶格 带隙 超原胞平面波展开法 

分 类 号：O737[理学—晶体学]