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The family of nanomagnetic arrays termed artificial spin ice (ASI) possess a vast range of metastable microstates. These states exhibit both exotic fundamental physics and more recently applied functionality, garnering attention as reconfigurable magnonic circuits and neuromorphic computing platforms. However, open questions remain on the role of microstate imperfections or angular disorder – particularly in the GHz response of the system. We report a study on the GHz dynamics of a series of five carefully prepared microstates in the same ASI sample, with both coexistence of vortex and uniformly magnetized macrospins, and disorder in the orientation of the macrospins at different vertices. We observe microstate-specific mode frequency shifting, mode creation and mode crossing. This versatility of characteristic spin-wave (SW) peaks for specific magnetic microstates in ASI enables identification of microstate configurations via SW spectral characterization. The wide reconfigurability of microstate-specific SW dynamics also opens avenues for developing rich magnonic devices operating in the GHz frequency regime and advances the understanding of ASI physics. [Display omitted] • Experimental and numerical study of reconfigurable magnonics in nanoscale artificial spin ice. • External field controlled magnetic microstate origami leads to rich magnon spectra. • BLS spectral fingerprinting of magnetic microstates leads to advancement of ASI physics. • Potential for on-chip data communication and processing using magnons in ASI systems. [ABSTRACT FROM AUTHOR]

Interfacial Dzyaloshinskii–Moriya interaction (IDMI) is crucial for stabilizing skyrmions and chiral domain walls, which are expected to play key roles in the development of advanced spintronics-based devices. Using Brillouin light scattering spectroscopy, we have directly measured the W-layer thickness-dependent IDMI in technologically important W(t)/CoFeB/SiO2 heterostructures in the range 1 nm ≤ t ≤ 7 nm. Due to the presence of IDMI, a pronounced asymmetry is observed in the peak intensity, frequency and linewidth of the spin-wave spectra in the Damon-Eshbach geometry. Our study reveals that IDMI energy density increases monotonically for 1 nm ≤ t ≤ 5 nm, beyond which it decreases sharply, while its sign always remains negative. This remarkable variation of IDMI energy density is explained in the light of the thickness-dependent structural phase transition of W. [ABSTRACT FROM AUTHOR]