Propagating photonic modes below the gap in a superconducting composite

Abstract

We show that there are propagating modes for electromagnetic waves in a periodic array of superconductor and insulator with two-dimensional symmetry. For waves polarized perpendicular to the array, the vector Maxwell equations reduce to a scalar wave equation for the nonvanishing component of electric field. This reduction is still valid if the superconducting component has an anisotropic dielectric tensor, as in the high-T, CuO-based materials. Using the Mattis-Bardeen form for the finite-frequency conductivity of a superconductor below its gap, the wave equation becomes formally identical to a Schrodinger equation. We give numerical examples for the case of a two-dimensional array of air cylinders embedded in a superconducting host. The results suggest that these modes may be observable in a highly anisotropic high-T, superconductor with c axis parallel to the direction of wave polarization.It has been known for several years that periodic dielectric arrays may have photonic band gapsthat is, frequency regimes where electromagnetic waves may not propagateeven if the dielectric functions of both constituents are real and positive. ' These materials are called photonic band-gap materials. Such band gaps may have many applications. For example, they may be useful as new types of electromagnetic filters in difficult-to-

A temperature modulation photonic crystal Mach-Zehnder interferometer composed of copper oxide high-temperature superconductor

“…[3][4][5][6] Integrated optical devices based on PCs become more and more attractive, and theoretical analysis has shown the possibility of high transmission efficiency in these devices. [17][18][19] In this paper we design a tunable PC Mach-Zehnder interferometer composed of copper oxide high-temperature su-perconductor utilizing the temperature modulation. Once the material and geometry structure of a PC are constructed, the possible way to change its PBSs is to tune the refractive indices of its constituent materials utilizing the temperature effect, the external electric field effect, the external magnetic field effect, etc.…”

One-dimensional photonic crystal with a complex defect containing an ultrathin superconducting sublayer

“…[4][5][6][7][8][9][10][11][12][13][14] Another group of unconventional materials for PCs, namely, superconductors was also studied in a number of theoretical publications for 1D and 2D PCs. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] All the articles related to superconducting ͑SC͒ PCs were investigating regular ͑nondefect͒ structures. The interest to the SC PCs is due to their applications in a new type of resonators 34 and microstrip filters based on YBa 2 Cu 3 O 7 which work in the gigahertz regime.…”

Photonic Band Structure and Transmittance of the Superconductor Photonic Crystal

“…However, Eq. (7) is still valid even for anisotropic materials (Lee et al, 1995). When the electric fields are parallel to the c-axis, plasma frequencies are in the microwave and farinfrared regions (Takeda & Yoshino, 2003e).…”