Harnessing Surface Plasmons for Magnetic Resonance Imaging Applications

Highly localized electromagnetic waves appearing in subwavelength structures, such as surface plasmons lying on a metal surface, are fundamental ingredients in nanophotonics since they offer novel routes for advanced subwavelength light control. Negative-magnetic-permeability metamaterials, already proposed for nuclear magnetic resonance imaging (MRI) applications, can also support magnetic-surface-plasmon excitations. Here we propose to exploit this phenomenon to increase MRI efficiency. We show that a negative-magnetic-permeability metamaterial slab, coupled to a standard radio-frequency surface coil, supports highly localized magnetic surface plasmons, allowing us to boost and to spatially manipulate the radio-frequency electromagnetic field. Our predictions indicate that the configuration considered holds great potential to enhance the MRI signal-to-noise ratio with respect to standard setups.