Design evaluation of microwave transmission properties of YBa2Cu3O7-based kinetic inductance detectors

Abstract

We designed, fabricated, and characterized microwave transmission properties with rewound strip structures for YBa _2 Cu _3 O _7 (YBCO)-based kinetic inductance detectors (KIDs). The superconducting rewound strip serves as a microwave resonator and as a broadband terahertz-wave antenna. To predict the microwave resonance characteristics before fabrication, the line-width ( w ) and space ( s ) dependence of the spiral resonators were analyzed using an electromagnetic simulator; the resonance frequency increased, and the quality factor decreased with increasing w and s from 10 to 40 μ m. YBCO-based KID arrays with different w (10 and 40 μ m) were fabricated on 10 mm-square MgO substrates, cooled to 3 K using a ^4 He refrigerator, and evaluated using a vector network analyzer to verify the result of the simulation experimentally. The measured resonance frequency ratio of 1.11 times (5.04 → 5.59 GHz) agreed with the simulated ones of 1.10 times (4.84 → 5.33 GHz) between w = 10 and 40 μ m. The other resonance characteristics, such as transmission coefficient and quality factor, have a similar w dependence with the simulation.

Keywords

• cuprate superconductor
• kinetic inductance detector
• terahertz detection technology