Abstract

A microwave kinetic inductance detector (MKID) is a cutting-edge superconducting detector. It comprises a resonator circuit constructed with a superconducting film on a dielectric substrate. To expand its field of application, it is important to establish a method to suppress the two-level system (TLS) noise that is caused by the electric fluctuations between the two energy states at the surface of the substrate. The electric field density can be decreased by expanding the strip width (S) and gap width from the ground plane (W) in the MKID circuit, allowing the suppression of TLS noise. However, this effect has not yet been confirmed for MKIDs made with niobium films on silicon substrates. In this study, we demonstrate its effectiveness for such MKIDs. We expanded the dimension of the circuit from (S, W) = (3.00 μm, 4.00 μm) to (S, W) = (5.00 μm, 23.7 μm), and achieved an increased suppression of 5.5 dB in TLS noise.

Details

Title
Characterization of two-level system noise for a microwave kinetic inductance detector comprising niobium film on a silicon substrate
Author
Sueno, Y 1 ; Honda, S 2 ; Kutsuma, H 3 ; Mima, S 4 ; Otani, C 5 ; Oguri, S 6 ; Suzuki, J 1 ; Tajima, O 1 

 Department of Physics, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 , Japan 
 Instituto de Astrofisica de Canarias , Calle Ví a Lá ctea, s/n, 38205 San Cristó bal de La Laguna, Santa Cruz de Tenerife , Spain 
 RIKEN Center for Quantum Computing (RQC), RIKEN , 2-1 Hirosawa, Wako, Saitama, 351-0198 , Japan 
 Superconductive ICT Device Laboratory, Kobe Frontier Research Center , Advanced ICT Research Institute, National Institute of Information and Communications Technology, 588-2 Iwaoka, Nishi-ku, Kobe, Hyogo, 651-2492 , Japan 
 Terahertz Sensing and Imaging Research Team , RIKEN 519-1399 Aramaki-Aoba, Aoba-ku, Sendai, 980-0845, Miyagi , Japan 
 Institute of Space and Astronautical Science (ISAS) , Japan Aerospace Exploration Agency (JAXA) 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 , Japan 
Publication year
2022
Publication date
Mar 2022
Publisher
Oxford University Press
e-ISSN
20503911
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3171492621
Copyright
© The Author(s) 2022. Published by Oxford University Press on behalf of the Physical Society of Japan. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.