三组元声子晶体中的缺陷态  

Defect states in three-component phononic crystal

作　　者：李晓春[1] 易秀英[1] 肖清武[1] 梁宏宇[1] 

机构地区：[1]中南大学物理科学与技术学院,长沙410083

出　　处：《物理学报》2006年第5期2300-2305,共6页Acta Physica Sinica

基　　金：湖南省自然科学基金(批准号:04JJ3079)资助的课题~~

摘　　要：运用基于平面波的超元胞方法,研究作为缺陷引入的第三组元材料(四氯化碳、水)对二维二组元声子晶体(水/水银,四氯化碳/水银)带结构的影响.结果表明,二组元声子晶体在引入第三组元点缺陷/线缺陷后,在原来的带结构中会出现缺陷态/带,原带隙的位置、宽度变化不大;缺陷态/带频率主要受第三组元材料物性参数的影响;这些缺陷态都是局域化的.因此,在具有宽带隙的二组元体系中引入适当的第三组元点缺陷/线缺陷,让缺陷态/带频率落在二组元体系的带隙中,就可以形成特殊的滤声态/波导态.声子晶体的这一特性对于声波/弹性波的传播和新的声学应用具有重要意义.Using the supereell plane wave method, we investigated the effect of the third component material as defects modifying band structure of two-dimension two-component phononic crystal （ PC）. It is shown that adding the third material as point defect/linear defects in the two-component PC, defect states/bands can appear in the original band gap whose position and width would have only minor changes. The frequency of the defect states/bands are affected by the third material＇ s characteristics; and all the defect states are localized. Therefore, adding proper third material as point/linear defects to the two-component system with wide band gap where defect states/bands will fall in, some special filtered/guided states will be formed. This property has important significance in acoustic/elastic wave propagating and new acoustic applications.

关 键 词：声子晶体 三组 点缺陷 线缺陷 

分 类 号：O735[理学—晶体学]