Noise Optimization for MKIDs with Different Design Geometries and Material Selections

• Published in: arXiv.org
• Main Authors: Pan, Z, Dibert, K R, Zhang, J, Barry, P S, Anderson, A J, Bender, A N, Benson, B A, Cecil, T, Chang, C L, Gualtieri, R, J Li, Lisovenko, M, Novosad, V, Rouble, M, Wang, G, Yefremenko, V
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 03.04.2023
• Subjects: Aluminum; Capacitors; Design optimization; Driving conditions; Elementary excitations; Inductance; Manganese; Niobium; Noise generation; Physics - Instrumentation and Detectors; Physics - Instrumentation and Methods for Astrophysics; Sensors; Thin films; White noise
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2304.01133

The separation and optimization of noise components is critical to microwave-kinetic inductance detector (MKID) development. We analyze the effect of several changes to the lumped-element inductor and interdigitated capacitor geometry on the noise performance of a series of MKIDs intended for millimeter-wavelength experiments. We extract the contributions from two-level system noise in the dielectric layer, the generation-recombination noise intrinsic to the superconducting thin-film, and system white noise from each detector noise power spectrum and characterize how these noise components depend on detector geometry, material, and measurement conditions such as driving power and temperature. We observe a reduction in the amplitude of two-level system noise with both an elevated sample temperature and an increased gap between the fingers within the interdigitated capacitors for both aluminum and niobium detectors. We also verify the expected reduction of the generation-recombination noise and associated quasiparticle lifetime with reduced inductor volume. This study also iterates over different materials, including aluminum, niobium, and aluminum manganese, and compares the results with an underlying physical model.