Angular-dependent dynamic response and magnetization reversal in Fibonacci-distorted kagome artificial spin ice

Abstract

We have measured the angular dependence of ferromagnetic resonance (FMR) spectra for Fibonacci-distorted, Kagome artificial spin ice (ASI). The number of strong modes in the FMR spectra depend on the orientation of the applied DC magnetic field. In addition, discontinuities observed in the FMR field-frequency dispersion curves also depend on DC field orientation, and signal a multi-step DC magnetization reversal, which is caused by the reduced energy degeneracy of Fibonacci-distorted vertices. The results suggest the orientation of applied magnetic field and severity of Fibonacci distortion constitute control variables for FMR modes and multi-step reversal in future magnonic devices and magnetic switching systems.

Direct observation of magnetic ordering induced via systematic lattice disorder in artificial rhombus spin ices

“…8 Controlling this additional level of frustration by controlling the ASI lattice geometry allows for the exploration of exotic collective behavior such as reduced dimensionality in 2D ASIs and extended magnetic frustration. 13,25 Recent efforts which investigated the dynamics of long-range disordered ASIs 26,27 have shown promise for the creation of rich magnonic systems. In addition, understanding the intricate interactions in progressively complex geometries like the Cayley tree 28 and Hopfield network 16 ASIs have successfully led to artificial spin-glass behavior.…”

Controlling the three dimensional propagation of spin waves in continuous ferromagnetic films with an increasing out of plane undulation

“…In the last decades, the conceptual problem was just studying SW propagation, which is inherently a two-dimensional problem, since a signal travelling along a waveguide can be embedded in one- (1D) or two-dimensional (2D) space, depending on the curvature 5 – 9 . Hence, the research exploration has mainly involved structures displaying 1D/2D magnetization textures, either periodic 10 – 13 or aperiodic 14 – 17 , while structures with in-plane periodicity, but inhomogeneous along the perpendicular direction, have been poorly explored so far. However, exploring the third dimension is crucial indeed, because a 3D distribution of the magnetization offers a new degree of freedom, which in general allows, from one side, to fit more functionality into a smaller space, and hence to considerably increase the density of elements in magnonic devices 18 , 19 , and from the other, further possibilities for the SW dynamics and transport (e.g., vertical magnon transport, nonreciprocal coupling 20 – 22 ).…”