Terahertz Resonators Based on YBa2Cu3O7 High-Tc Superconductor

Abstract

Superconducting split-ring resonator arrays allow to overcome two main limitations affecting metallic metamaterial resonating in the terahertz (THz) range: ohmic losses and tunability of their optical response. In this work, we design and experimentally realize direct and complementary square arrays of superconducting YBa2Cu3O7 (YBCO) split-ring resonators working in the THz spectral range. The main purpose of this paper is to show how the metamaterial resonances can be tuned by temperature (T) when crossing the superconducting transition temperature Tc of YBCO. The tuning property can be quantified by describing the THz transmittance of the patterned YBCO films vs. T through a model of coupled resonators. This model allows us to estimate the THz resonances of split-ring arrays and their interaction, showing how the kinetic inductance Lk in the superconducting state is the main parameter affecting the metamaterial properties.

Strong coupling of metamaterials with cavity photons: toward non-Hermitian optics

“…Superconducting elements can provide tunable electromagnetic properties, as they are sensitive to a variety of external disturbances such as temperature, magnetic field, electric current, and optical radiation. For example, high-Tc superconducting YBa 2 Cu 3 O 7 split-ring resonators have recently been reported with tunability of the resonance frequency (up to 4 THz) by temperature [ 61 ]. Moreover, ohmic losses of superconductors are low up to a certain cutoff frequency and independent of the dimension of the component, which is highly advantageous for increasing the Q-factor of polariton modes [ 62 ].…”

Tensile Microstrain Fluctuations in the BaPbO Units in Superconducting BaPb1−xBixO3 by Scanning Dispersive Micro-XANES

“…The critical temperature of the superconducting transition and electronic structure at the Fermi level in quantum complex matter and high temperature superconductors is governed not only by doping, but also by the lattice strain in nickelates, iron-based superconductors, and heterostructures controlling the complex landscape generated by nanoscale phase separation [24][25][26][27][28][29] near the superconductor-insulator transition [30], as it was first shown in cuprates and diborides [18][19][20][21][22][23]. In this work we apply scanning µ-X-ray absorption near edge structure (SµXANES) to unveil the spatial heterogeneity of local lattice fluctuations [31][32][33][34][35] in a selected nanocluster related to the strain at specific sites, namely, microstrain spatial fluctuations near the metal to insulator transition in BaPb 1−x Bi x O 3 .…”

“…While it is known that a misfit strain generates a complex nanoscale phase separation in cuprates [19][20][21][22][23][24][25][26][27][28] and iron-based superconductors with a percolative network, the misfit strain in Ba(Pb 1−x Bi x )O 3 has not yet been reported. In this work, we have used SµXANES to investigate the spatial distribution of microstrain in three BaPb 1−x Bi x O 3 samples with x = 0, 0.19 and 0.28 (full red circles in Figure 1b) to obtain a deeper insight into the relationship between local lattice inhomogeneity and superconductivity in this system.…”

Terahertz and Infrared Plasmon Polaritons in PtTe2 Type‐II Dirac Topological Semimetal

“…These features, providing optical tunability and control in specific spectral bandwidths, fostered widespread technological applications in the last decades spanning from nano‐infrared (IR) and surface‐enhanced Raman spectroscopies, [ 2 ] to sensing techniques. [ 3,4 ] Although conventional metals are the usual means to generate SPPs, [ 1 ] nonconventional conductors like transparent oxides, [ 5 ] high‐ T c superconductors, [ 6–8 ] strongly‐correlated oxides, [ 9,10 ] graphene, [ 11–13 ] were recently proven to host SPPs with tailored properties by design owing to their extreme sensitivity to doping, temperature, electric and magnetic fields.…”