Analysis and Performance of Lumped-Element Kinetic Inductance Detectors for W-Band

• Published in: IEEE transactions on microwave theory and techniques Vol. 69; no. 1; pp. 578 - 589
• Main Authors: Aja, Beatriz, de Ory, Marina C., Fuente, Luisa de la, Artal, Eduardo, Pascual, Juan Pablo, Magaz, Maria Teresa, Granados, Daniel, Gomez, Alicia
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum; Ambient temperature; Arrays; Coupling; Cryoforming; Cryogenic temperature; Cryogenics; Detectors; Dual polarization (waves); Inductance; kinetic inductance detector (KID); lumped-element resonator; Millimeter waves; millimeter-wave astronomy; Optimization; polarimetry; Quantum computing; Resonators; Sensors; Silicon; Silicon substrates; Strips; Substrates; Superconducting microwave devices; Superconductivity; Telescopes; Thin films; Titanium; Tungsten
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2020.3038777

Lumped-element superconducting resonators are a promising technology for their use in millimeter-wave observations and quantum computing applications that require large arrays of extremely sensitive detectors. Among them, lumped-element kinetic inductance detectors (LEKIDs) have shown good performance in the submillimeter band in several earth-based telescopes. In this work, LEKIDs for their use as millimeter-wave receivers of astronomical applications are presented. LEKID arrays using a thin bilayer of superconducting titanium/aluminum (Ti/Al), deposited on the silicon substrate, have been designed and fabricated. The design of a dual-polarization LEKID with the goal of detection at the <inline-formula> <tex-math notation="LaTeX">W </tex-math></inline-formula>-band for two orthogonal polarizations is described and a fabricated array has demonstrated absorption at ambient temperature. Also, an approximate design methodology of the coupling parameter for LEKIDs' readout, essential for dynamic range optimization of the detector under millimeter-wave radiation, is proposed. In addition, the resonance characteristics and coupling factor of the fabricated superconducting resonators using high-quality internal factor <inline-formula> <tex-math notation="LaTeX">Q_{i} </tex-math></inline-formula> under cryogenic temperatures have been analyzed. The design guidelines in this work are applicable to other LEKID arrays, and the presented superconducting Ti/Al thin-film LEKIDs can be used in future receiver arrays in the millimeter bands.