Experimental realisation of tunable ferroelectric/superconductor $$({\text {B}} {\text {T}} {\text {O}}/{\text {Y}} {\text {B}}{\text {C}} {\text {O}})_{{\text {N}}}/{\text {S}}{\text {T}}{\text {O}}$$ 1D photonic crystals in the whole visible spectrum

Abstract

Emergent technologies that make use of novel materials and quantum properties of light states are at the forefront in the race for the physical implementation, encoding and transmission of information. Photonic crystals (PCs) enter this paradigm with optical materials that allow the control of light propagation and can be used for optical communication, and photonics and electronics integration, making use of materials ranging from semiconductors, to metals, metamaterials, and topological insulators, to mention but a few. Here, we show how designer superconductor materials integrated into PCs fabrication allow for an extraordinary reduction of electromagnetic waves damping, making possible their optimal propagation and tuning through the structure, below critical superconductor temperature. We experimentally demonstrate, for the first time, a successful integration of ferroelectric and superconductor materials into a one-dimensional (1D) PC composed of (BTO/YBCO) N /STO bilayers that work in the whole visible spectrum, and below (and above) critical superconductor temperature T C = 80 K. Theoretical calculations support, for different number of bilayers N, the effectiveness of the produced 1D PCs and may pave the way for novel optoelectronics integration and information processing in the visible spectrum, while preserving their electric and optical properties. The use of electromagnetic (EM) waves as information carriers for communication systems has been in place for many years 1,2 ; as such, EM wavelengths make possible the transmission over large distances but, at the same time, they limit the amount of information they can convey by their frequency: the larger the carrier frequency, the larger the available transmission bandwidth and thus the information-carrying capacity of the communication system 3. For this reason, quantum artificial nanostructured materials such as photonic crystals that are able to transmit at high frequencies and that concentrate the available power within the transmitted electromagnetic wave, thus giving an improved system performance, are desired 4. PCs are artificial periodic structures characterised by a periodic variation of the refractive index with a consequent periodic spatial variation of the dielectric constant, which may be tailored to control light properties 4. They, therefore, allow the appearance of defined frequency ranges and address the issue of forbidden/allowed propagation of electromagnetic waves. As a consequence, the control and tunability of PCs opens a new perspective for information processing and technological

Optical Properties of One‐Dimensional Photonic Crystal Composed of Superconductor and Dielectric Layers with Liquid Crystal Layer as Defect

“…Some experimentalists [ 20 ] have demonstrated a successful integration of ferroelectric and superconductor materials into 1DPC composed of (BTO/YBCO) N /STO bilayers that work in the whole visible spectrum, below and above critical temperature 𝑇 = 80 K, for a chosen superconductor. They provided a robust integration of ferroelectric‐superconductor 1DPC heterostructure having remarkable optical properties that can be employed in optoelectronics integration and optical communication.…”