Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN, Brazil.
J Phys Condens Matter. 2013 Jul 17;25(28):286002. doi: 10.1088/0953-8984/25/28/286002. Epub 2013 Jun 19.
We employ a microscopic theory to investigate spin wave (magnon) propagation through their dispersion and transmission spectra in magnonic crystals arranged to display deterministic disorder. In this work the quasiperiodic arrangement investigated is the well-known generalized Fibonacci sequence, which is characterized by the σ(p,q) parameter, where p and q are non-zero integers. In order to determine the bulk modes and transmission spectra of the spin waves, the calculations are carried out for the exchange dominated regime within the framework of the Heisenberg model and taking into account the random phase approximation. We have considered magnetic materials that have a ferromagnetic order, and the transfer-matrix treatment is applied to simplify the algebra. The results reveal that spin wave spectra display a rich and interesting magnonic pass- and stop-bands structures, including an almost symmetric band gap distribution around of a mid-gap frequency, which depends on the Fibonacci sequence type.
我们采用微观理论研究了自旋波（磁振子）的传播，通过它们在呈现确定性无序的磁性晶体中的色散和传输谱来研究。在这项工作中，研究的准周期排列是众所周知的广义 Fibonacci 序列，其特征是 σ(p,q)参数，其中 p 和 q 是非零整数。为了确定自旋波的体模和传输谱，我们在海森堡模型的框架内，在交换主导的条件下进行计算，并考虑了随机相位近似。我们考虑了具有铁磁有序的磁性材料，并且应用转移矩阵处理来简化代数。结果表明，自旋波谱显示出丰富而有趣的磁性通带和截止带结构，包括在中频附近几乎对称的带隙分布，这取决于 Fibonacci 序列类型。
