Huge Electric Field Enhancement of Magnetic Resonator Integrated with Multiple Concentric Rings

In this paper, a magnetic resonator (MR) integrated with multiple concentric rings with field enhancement (| E |/| E 0 |) up to a nearly 3 orders of magnitude 10 3 is proposed theoretically. The underlying physical mechanism of the huge field enhancement originates from two parts: the field concentration induced by the multiple rings and the self-resonance of the MR. To account for the field enhancement caused by the multiple rings, an analytical model taking into account the absorption and scattering of surface plasmon polariton (SPP) through the rings is presented, which is in good agreement with the simulation results. Our work provides a theoretical guidance for the optimal design of the nanostructures with large field enhancement, which shows great potential for the application of highly sensitive surface-enhanced Raman scattering (SERS) in single-molecule detection.