Plasmonic nanoloops have been shown to be capable candidates for creating building blocks of metasurfaces to manipulate light in desired ways. Multimaterial loop metasurfaces offer astonishing design flexibility for various purposes. Concentric loop nanoantennas can couple to each other strongly or weakly based on the relevant designs. The low-coupled multimaterial loops can be employed as a frequency selective surface with a number of separated bands. On the other hand one can take advantage of high coupling between the loops to achieve two different resonances; one will be a very high and sensitive mode and the other a radiating wideband low-loss resonance. In both resonances the building block has a subwavelength size. Here the performance of a periodic array of multimaterial loops is investigated by means of the finite-difference time-domain technique. Based on the performance of a single plasmonic loop building block with general Drude material the behavior of the multimaterial loop metasurface is investigated. We show how choosing the proper materials can control the resonance characteristics. The performance of multimaterial loops is studied by utilizing the induced net dipole moments on the concentric loops and appearance of Fano-like resonance in the high-coupled case is demonstrated. Moreover, the large field enhancement as a result of a subradiant resonance is studied. The sensitivity of the structure to the spacer layer permittivity and loss are investigated in detail.
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