Fig. 2: 2D spoof magnetic plasmons with near-equidistant multi-resonant response supported within a deeply subwavelength space-coiling cylinder.
a Scattering spectrum of a PEC space-coiling cylinder with spiral turns nr = 100, duty cycle a/d = 2/3, illuminated by a TM plane wave. The upper insets show the enlarged scattering spectrum, magnetic field (H), surface current (J), and electric field (E) patterns of the fundamental mode, and schematic of the structure. The lower insets show the magnetic field patterns for higher-order resonance modes. b Magnetic field enhancement of the resonant modes along the radial direction, normalized to the impinging field. c Normalized resonant frequency k0R of the first 16 modes. d Resonant wavelength of the fundamental mode as a function of the spiral turn number nr. (e) Field enhancement and quality factor as a function of nr2.
