物理学报2012，Vol.61Issue(23)：294-300,7.
晶格中心插入体的对称性及取向对二维声子晶体带隙的影响
The two-dimensional phononic crystal band gaps tuned by the symmetry and orientation of the additional rods in the center of unit cell
摘要
Abstract
The effects of symmetry and orientation of the additional steel rods on the band gaps of two-dimensional phononic crystals with steel-air system are numerically investigated by using the plane wave expansion method. The original steel rods of the phononic crystals are of columns in square and hexagonal lattices, and the additional steel rods are of regular square, hexagon, octagon prisms and columns, which are placed, respectively, in the center of each unit cell of the two kinds of lattices. The gap maps are introduced to illustrate the influences of the filling fraction and orientation of the additional rods on band gaps. It is found that in the case of the additional rods with low filling fraction, the band gaps can be obtained most easily because the degeneracy of bands is lifted when the cross section of additional rod has the same shape as that of lattice, but the widest band gaps appear under the condition of the additional rods with highest symmetry and largest filling fraction. The influence of orientation on band gap in square lattice is more obvious than that in hexagonal lattice. If the column lattice points are changed by square prisms in simple square lattice, the lower and wider band gaps can be produced by rotating the square prisms, which is contrary to the scenario that emerges in square lattice with additional rods at the center of unit cell. Using one of the methods of adding additional rods or rotating the original prisms is more beneficial to the generation of band gaps than combining effect of these two means in simple lattices. Furthermore, the mechanisms of above results are analyzed.关键词
声子晶体/能带结构/带隙/平面波法Key words
phononic crystal/band structure/band gap/plane wave expansion method分类
数理科学引用本文复制引用
胡家光,徐文,肖宜明,张丫丫..晶格中心插入体的对称性及取向对二维声子晶体带隙的影响[J].物理学报,2012,61(23):294-300,7.基金项目
国家自然科学基金（批准号：10974206）资助的课题. （）
