Experimental realization of an achromatic magnetic mirror based on metamaterials

Our work relates to the use of metamaterials engineered to realize a metasurface approaching the exotic properties of an ideal object not observed in nature, a "magnetic mirror." Previous realizations were based on resonant structures that implied narrow bandwidths and large losses. The working principle of our device is ideally frequency-independent, it does not involve resonances and it does not rely on a specific technology. The performance of our prototype, working at millimeter wavelengths, has never been achieved before and it is superior to any other device reported in the literature, both in the microwave and optical regions. The device inherently has large bandwidth (144%), low losses (