Herein we experimentally study magnetic multilayer metamaterials with broken translational symmetry. Epitaxially-grown iron-gold (Fe-Au) multilayers modulated using Fibonacci sequence—referred to as magnetic inverse Fibonacci-modulated multilayers (IFMs)—are prepared using ultra-high-vacuum vapor deposition. Experimental results of in-situ reflection high-energy electron diffraction, magnetization curves, and ferromagnetic resonance demonstrate that the epitaxially-grown Fe-Au IFMs have quasi-isotropic magnetization, in contrast to the in-plane magnetization easy axis in the periodic multilayers.

We study optical and magneto-optical (MO) properties of epitaxially grown modulated Fe-Pt multilayer metamaterials by means of generalized MO ellipsometry (GME). Large Kerr rotation, ellipticity, and MO coupling parameters in the visible and near-infrared regions are obtained for modulated metamaterials, in which the stacking sequences follow an inverse Fibonacci series. In contrast, periodic multilayers show small MO parameters, although they otherwise exhibit magnetic and optical properties that are very similar to those for the modulated metamaterials. The present study demonstrates that specific thickness modulation can have a significant materials design potential for one-dimensional magnetic metamaterials.