Nanochannels for spin-wave manipulation in Ni80Fe20 nanodot arrays

•Spin wave dynamics of connected nanodots array.•Role of nanochannels to tune the spin-wave modes of nanodots.•Frequency selective spin wave propagation through nanochannels leading towards one-to-four magnonic demultiplexer logic operations. Patterned magnetic nanostructures are potential candidates for future energy efficient, on-chip communication devices. Here, we have studied experimentally and numerically the role of nanochannels to manipulate spin waves in Ni80Fe20 connected nanodot arrays of varying filling fraction. Rich spin-wave spectra are observed in these sample, where the number of spin-wave modes decreases with increasing filling fraction due to the reduction in the demagnetization field. The nanochannels affect the spin-wave modes of the connected dots by modified magnetic coupling as well as selective channelling of spin-wave modes. For all modes, the vertical nanochannels couple the nanodots, except for the highest frequency mode where all nanochannels act as coupler. This feature is further explored in the simulation, which reveals that only the highest frequency mode can propagate through all the nanochannels, which may be further exploited to construct an electronic demultiplexer. This study will be useful to understand the role of nanochannels in patterned magnetic nanostructures and their applications in spin-wave based communication devices.