Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Engineering Beyond the Standard Quantum Limit: Lie-Algebraic Observable-Dependent Renormalization for Josephson Parametric Amplifiers and SQUID Quantum Sensors

Isamu Ohnishi, Chavis Srichan

Published Jan 1, 2026• 0 citations
Publisher
DOI
10.2139/ssrn.7296580

Related papers

Broadband Josephson parametric amplifiers: Beyond the standard gain-bandwidth product

Tanay Roy, S. Kundu, Madhavi Chand +7 more

Bulletin of the American Physical Society•Mar 17, 2016•0 citations

Quantum Learnable Geometry and Lie-Algebraic Observable-Dependent Renormalization

Chavis Srichan, Isamu Ohnishi

•Jan 1, 2026•0 citations

Development of SQUID Amplifiers for Axion Search Experiments

Sergey V. Uchaikin, Andrei N. Matlashov, Doyu Lee +11 more

We report results of our development of two types of microwave amplifiers based on Superconducting quantum interference devices (SQUIDs) for CAPP (Center for Axion and Precision Physics Research) axion search experiments. The first amplifier, Microstrip SQUID Amplifier (MSA) has a wide bandwidth. Power dissipation in resistive shunts results in a device overheating and limits the MSA performances. A thermal models of shunt cooling processes is developed and recommendations for a future design is provided. The second amplifier, Josephson Parametric Amplifier (JPA), at limited bandwidth showed a low noise near the standard quantum limit (SQL) of 196 mK. Implementation of a JPA in CULTASK (CAPP's Ultra-Low Temperature Axion Search in Korea) experiment is planned in the end of 2019.

IEEE International Superconductive Electronics Conference (ISEC)•Jul 1, 2019•3 citations

Enhanced Dynamic Range in $N$-SQUID Lumped Josephson Parametric Amplifiers

Andrew Eddins, Eli M. Levenson-Falk, D.M. Toyli +3 more

Bulletin of the American Physical Society•Mar 5, 2014•0 citations

Understanding the Saturation Power of Josephson Parametric Amplifiers Made from SQUID Arrays

Luca Planat, Rémy Dassonneville, Javier Puertas Martínez +7 more

Josephson parametric amplifiers (JPAs) are key devices in superconducting quantum circuits, as they ultimately dictate quantum efficiency and speed of measurement, but they still suffer from low saturation power. This work shows that a JPA's saturation power can be increased by using a Josephson-junction array, rather than a single-junction amplifier. Modeling such an array as a nonlinear $L\phantom{\rule{0}{0ex}}C$ resonator reproduces the observed amplification and saturation effects very well. This use of arrays to fight low power saturation is easy to implement, and can be directly combined with impedance-engineered environments to enhance dynamic range even more.

arXiv:1809.08476•Physical Review Applied•Mar 6, 2019•54 citations

Lie-Algebraic Observable-Dependent Renormalization for Model Reduction in Open Quantum Dynamics

Isamu Ohnishi

•Jan 1, 2026•0 citations
We report results of our development of two types of microwave amplifiers based on Superconducting quantum interference devices (SQUIDs) for CAPP (Center for Axion and Precision Physics Research) axion search experiments. The first amplifier, Microstrip SQUID Amplifier (MSA) has a wide bandwidth. Power dissipation in resistive shunts results in a device overheating and limits the MSA performances. A thermal models of shunt cooling processes is developed and recommendations for a future design is provided. The second amplifier, Josephson Parametric Amplifier (JPA), at limited bandwidth showed a low noise near the standard quantum limit (SQL) of 196 mK. Implementation of a JPA in CULTASK (CAPP's Ultra-Low Temperature Axion Search in Korea) experiment is planned in the end of 2019.
Enhanced Dynamic Range in NNN-SQUID Lumped Josephson Parametric Amplifiers
Josephson parametric amplifiers (JPAs) are key devices in superconducting quantum circuits, as they ultimately dictate quantum efficiency and speed of measurement, but they still suffer from low saturation power. This work shows that a JPA's saturation power can be increased by using a Josephson-junction array, rather than a single-junction amplifier. Modeling such an array as a nonlinear $L\phantom{\rule{0}{0ex}}C$ resonator reproduces the observed amplification and saturation effects very well. This use of arrays to fight low power saturation is easy to implement, and can be directly combined with impedance-engineered environments to enhance dynamic range even more.