Tunable Negative Permeability in a Three-Dimensional Superconducting Metamaterial

Abstract

We report on highly tunable radio-frequency (rf) characteristics of a low-loss and compact threedimensional (3D) metamaterial made of superconducting thin-film spiral resonators. The rf transmission spectrum of a single element of the metamaterial shows a fundamental resonance peak at ∼24.95 MHz that shifts to a 25% smaller frequency and becomes degenerate when a 3D array of such elements is created. The metamaterial shows an in situ tunable narrow frequency band in which the real part of the effective permeability is negative over a wide range of temperature. This narrow frequency band gradually possesses near-zero and positive values for the real part of permeability as the superconducting critical temperature is approached. The studied 3D metamaterial can be used for increasing power-transfer efficiency and tunability of electrically small rf antennas.

Negative permittivity adjusted by SiO2-coated metallic particles in percolative composites

“…For example, negative permittivity with small value is required for impendence matching with negative permeability materials. [27] And negative permittivity with small value must be satisfied to excite surface plasma polarization for noble metal particles when used as biosensing at optical spectrum. [9] Besides, the capacitance enhancement, which is significant for miniaturization of electronic component, would be remarkable especially when the negative permittivity matches with positive permittivity based on the principle of series capacitor.…”

Tuning of Strong Nonlinearity in rf SQUID Meta-Atoms

“…[48] This design could be useful for a tunable plasmonic haloscope to detect candidate axionic dark matter particles. [49] All of the superconducting metamaterials discussed above display strong signatures of nonlinearity, [50][51][52][53][54] even to the single-photon limit. Here we are interested in characterizing and understanding the nonlinear properties of individual rf SQUIDs, which can help inform the behavior of metamaterials made up of such objects.…”

Wideband and polarisation‐independent antireflection coating using metamaterials

“…Metamaterials properties are mainly determined by their structures not from the properties of their base compositions [1,2]. Metamaterials can be engineered to have the negative refractive index [3], the zero refractive index [4], tunable negative permeability [5], high index of refraction [6], anomalous dispersion [7], optical magnetism [8] and other electromagnetic properties that cannot be found in the nature. These properties have been widely used in a variety of applications over wide frequency ranges, for instance, THz switches and modulators [9,10], high-resolution magnetic resonance radio-frequency imaging [11], super-directive and super-conductive antennas.…”

“…The exotic properties of MMs come from their structuration, as well as the properties of their inclusions [1, 2]. Within the last few years, MMs have broadly employed to achieve a large variety of exotic phenomena, not readily achievable with natural materials, such as negative refractive index [3], the zero refractive index [4], tunable negative permeability [5], high index of refraction [6], anomalous dispersion [7], optical magnetism [8], to name a few. These features have held great promises for the realisation of a broad range of devices such as switches and modulators [9, 10], high‐resolution magnetic resonance radio‐frequency imaging [11], super‐directive and super‐conductive antennas [12–15].…”