We have experimentally and numerically investigated the dispersion of collective spin waves prop-agating through arrays of longitudinally magnetized nanowires with periodically modulated width. Two nanowire arrays with single-side modulation and different periodicity of modulation were studied and compared to the nanowires with homogeneous width. The spin-wave dispersion, meas-ured up to the third Brillouin zone of the reciprocal space, revealed the presence of two dispersive modes for the width-modulated NWs, whose amplitude of magnonic band depends on the modula-tion periodicity, and a set of nondispersive modes at higher frequency. These findings are different from those observed in homogeneous width NWs where only the lowest mode exhibits sizeable dis-persion. The measured spin-wave dispersion has been satisfactorily reproduced by means of dynam-ical matrix method. Results presented in this work are important in view of the possible realization of frequency tunable magnonic device.

中文翻译：

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具有单侧周期性调制宽度的坡莫合金纳米线阵列中的集体自旋波

我们已经通过实验和数值研究了通过具有周期性调制宽度的纵向磁化纳米线阵列传播的集体自旋波的色散。研究了具有单侧调制和不同调制周期的两种纳米线阵列，并与具有均匀宽度的纳米线进行了比较。测量到倒易空间的第三布里渊区的自旋波色散揭示了宽度调制的 NW 存在两种色散模式，其磁子带的幅度取决于调制周期，以及一组高频下的非色散模式。这些发现不同于在均匀宽度 NW 中观察到的发现，其中只有最低模式表现出相当大的色散。测量的自旋波色散已通过动态矩阵方法得到令人满意的再现。鉴于频率可调磁子器件的可能实现，这项工作中提出的结果很重要。