Spin-wave localization on phasonic defects in one-dimensional magnonic quasicrystal

Abstract

We report on the evolution of the spin-wave spectrum under induced structural disorder in onedimensional magnonic quasicrystal. We study theoretically a system composed of ferromagnetic strips arranged in a Fibonacci sequence for several stages of disorder in the form of phasonic defects, where different rearrangements are introduced. By transition from the quasiperiodic order towards disorder, we show a gradual degradation of the fine fractal spectra of spin-waves, and the evolution of the band gaps. The analysis shows the mode localization evolution, which is an inevitable property of the quasicrystals. In particular, significant enhancement of the spin-wave mode localization and disappearing of the van Hove singularities at the band gap edges with increasing number of defects can be indication of the phasonic defects existing in the structure. This work fills gap in the knowledge of defected magnonic Fibonacci quasicrystals and opens the way to the study of the phasonic defect in two-dimensional magnonic quasicrystals.