Active Terahertz Modulator and Slow Light Metamaterial Devices with Hybrid Graphene-superconductor Coupled Split-ring Resonator Arrays

Abstract

The dynamically tunable terahertz (THz) waves and electromagnetically induced transparency (EIT) in coupled hybrid superconducting niobium-graphene split-ring resonator arrays are investigated. Active modulation of THz waves is studied through two different approaches. Thermal tuning of THz amplitude and group delay is observed due to the temperature sensitivity of the niobium superconductor. Stronger photoresponses are observed when niobium is superconducting. The electrical tuning of the integrated hybrid device is accomplished through the integration of graphene patches with the superconducting circuit. The modulation of resonance strength and group delay is observed due to damping of the dark mode resonance in coupled split-ring resonator arrays. The proposed chip-scale device provides a route toward the implementation of active cryogenic THz devices.

Millimeter-Waves to Terahertz SISO and MIMO Continuous Variable Quantum Key Distribution

“…Recently, devices for mm-waves to THz frequency range based on superconductors operating at temperature ranges from 4K to 80K [3] such as efficient coherent emitters [18], THz photonic circuits [46], etc have been proposed, which could be the possible solution of building the cryogenic mm-wave to THz quantum communication link. The superconducting-based coherent THz source has been reported to generate high-power THz radiation (> μ W) below 50K [85] that abandons the complicated terahertz-optics conversion and is suitable for onchip mm-waves and THz waves transmission.…”

“…A gap in the electromagnetic spectrum exists at these frequency ranges due to the inefficient and unpractical of the devices and circuits [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. However, the recent development of electronic, photonic and plasmonic-based mm-waves and THz technologies help close this gap with the demonstration of power-efficient sources [20][21][22][23][24][25][26], antennas [27][28][29][30][31], filters [32][33][34], waveguides [29,[35][36][37][38][39], modulators [40][41][42][43][44][45][46][47][48]…”