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Abstract:

We report on the first observation of an exact fractal pattern in the time-domain arising spontaneously from adynamic artificial crystal (DAC). The all-magnon process occurs in a passive, unlithographed magnetic wave-guide. The DAC was created by a standing spin wave of frequency ƒ_DAC in a region of nonlinear waveguide, resulting in a spatio-temporally periodic potential. The interaction of travelling spin waves of frequency ƒ′ with the DAC resulted in a series of new modes appearing in a comb with intervals Δƒ⁽⁰⁾ = | ƒ_DAC − ƒ′|. As the magnetic field H was increased a 1st pre-fractal pattern was observed with frequency interval Δƒ⁽¹⁾ = Δƒ⁽⁰⁾/2. Finally, the onset of a 2nd pre-fractal was observed with frequency interval Δƒ⁽²⁾ = Δƒ⁽¹⁾/2 = Δƒ⁽⁰⁾/4. The magnetic field dependence of the nonlinear signals matched that of the DAC. The spin wave fractal behavior was demonstrated for different values of ƒ′.

Abstract:

Magnonic circuit elements generally operate using signals that are either amplitude or phase modulated. We propose a simple all-magnon circuit element capable of converting between these two types of encoding, and 91̽�� our design with simulations. We highlight the potential of our technique to augment existing devices and propose an alternative schematic for an “equality” gate and exclusive nor gate.