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

Approaching the Quantum Limit in Axion Detection at IBS-CAPP and IBS-DMAG

Sergey V. Uchaikin, Boris I. Ivanov, Arjan F. van Loo, Yasunobu Nakamura, MinSu Ko, Jinmyeong Kim, Saebyeok Ahn, Seonjeong Oh, Yannis Kyriakos Semertzidis, SungWoo Youn

Published Nov 26, 2025• 0 citations
Publisher

Abstract

We present the development of two complementary amplifier architectures for axion haloscope experiments, based on two types of Josephson Parametric Amplifiers (JPAs).The first employs a multi-chip module of flux-driven JPAs in a parallel-series configuration, enabling near quantum-limited amplification over an extended tunable range of between 1.2 and 1.5 GHz.The second design features a lumped-element JPA, offering continuous tunability across a wide frequency range from 2.4 to 4 GHz.Both approaches demonstrate near-quantum-limited noise performance and are compatible with operation in cryogenic environments.These amplifiers significantly enhance the sensitivity and frequency coverage of axion search experiments, and also provide new opportunities for broadband quantum sensing applications.

DOI
10.3390/psf2025011005

Related papers

Multi-JPA configuration to broaden amplification bandwidth for axion haloscope experiments

Boris I. Ivanov, Sergey V. Uchaikin, Jinmyeong Kim +7 more

Abstract Josephson parametric amplifiers (JPAs) are used in a wide range of applications, including quantum sensing and axion dark matter searches, due to their near-quantum-limited noise performance. In this article, we present a novel amplifier configuration that increases the frequency scanning range for axion search experiments by combining six narrow-band, flux-driven JPAs. The design consists of two subsets, each comprising three JPAs connected in parallel and coupled to one of two circulators. These subsets are arranged in series. A single pump tone is split and distributed across all JPAs. We effectively mitigated challenges associated with frequency tuning and cross-talk arising from JPA band overlap while maintaining low noise performance. To validate this configuration, we implemented a JPA system spanning 1.2–1.5 GHz as the first-stage amplifier in an RF chain, where the total noise was measured to be approximately twice the standard quantum limit.

Superconductor Science and Technology•Jan 19, 2026•0 citations

Improving Amplification Bandwidth by Combining Josephson Parametric Amplifiers for Active Axion Search Experiments at IBS/CAPP

Sergey V. Uchaikin, Jinmyeong Kim, Boris I. Ivanov +8 more

Abstract IBS/CAPP in South Korea is home to multiple active axion search experiments using cavity haloscopes that operate within the frequency range of 1-6 GHz. The haloscopes convert axions to photons, resulting in an output power of about 10-24 to 10-22 W. To detect such a small signal amidst noise, quantum-limited noise amplifiers and ultra-low-temperature environment (∼10 mK) are required for all critical read-out components to minimize noise from all of active and passive lossy components. Additionally, operating at low dissipation levels is necessary to maintain the haloscope and amplifier at a temperature of 25-40 mK. Our primary objective is to achieve the highest possible scanning-frequency speed, which includes the time for maintenance and system calibration. For the CAPP-MAX flagship experiment, we achieved a record speed of 3 MHz/day for the DFSZ-level axion sensitivity during uninterrupting measurements. This paper presents the development and operation of low-noise amplifiers for five haloscope experiments targeting different frequency ranges and provides design, operational, and performance details of the amplifiers.

Journal of Low Temperature Physics•Jul 1, 2024•5 citations

Characterization of a flux-driven Josephson parametric amplifier with near quantum-limited added noise for axion search experiments

Çağlar Kutlu, Arjan F. van Loo, Sergey V. Uchaikin +7 more

Abstract The experimental non-observation of charge-parity (CP) symmetry violation in quantum chromodynamics is commonly referred to as the strong CP problem. The axion, a hypothetical elementary pseudoscalar, is expected to solve the strong CP problem and is also a promising candidate for dark matter. The most sensitive axion search experiments operate at millikelvin temperatures and hence rely on instrumentation that carries signals from a system at cryogenic temperatures to room temperature instrumentation. One of the biggest limiting factors affecting the parameter scanning speed of these detectors is the noise added by the components in the signal detection chain. Since the first amplifier in the chain limits the minimum noise, low-noise amplification is of paramount importance. This paper reports on the operation of a flux-driven Josephson parametric amplifier (JPA) operating at around 2.3 GHz with added noise approaching the quantum limit. The JPA was employed as a first stage amplifier in an experimental setting similar to the ones used in haloscope axion detectors. By operating the JPA at a gain of 19 dB and cascading it with two cryogenic amplifiers operating at 4 K, noise temperatures as low as 120 mK were achieved for the whole signal detection chain.

arXiv:2101.08496•Superconductor Science and Technology•Mar 25, 2021•43 citations

Wideband Amplification for IBS-CAPP's Axion Search Experiments

Jinmyeong Kim, Minsu Ko, Sergey V. Uchaikin +7 more

Abstract We present a novel amplifier configuration that combines six relatively narrow-band flux-drive Josephson Parametric Amplifiers (JPAs) to extend the bandwidth for the axion search experiments. We have addressed challenges related to the tuning and cross-talk resulting from JPA band overlap while maintaining low noise levels. Our measurements demonstrate that the added noise by an RF chain, with the JPA acting as the primary stage amplifier, remains between 75 and 175 mK from 1.19 to 1.33 GHz and from 1.36 to 1.5 GHz.

•Nov 7, 2023•1 citation

Josephson parametric amplifier based quantum noise limited amplifier development for axion search experiments in CAPP

Sergey V. Uchaikin, Jinmyeong Kim, Çağlar Kutlu +8 more

This paper provides a comprehensive overview of the development of flux-driven Josephson Parametric Amplifiers (JPAs) as Quantum Noise Limited Amplifier for axion search experiments conducted at the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science. It focuses on the characterization, and optimization of JPAs, which are crucial for achieving the highest sensitivity in axion particle detection. We discuss various characterization techniques, methods for improving bandwidth, and the attainment of ultra-low noise temperatures. JPAs have emerged as indispensable tools in CAPP’s axion search endeavors, playing a significant role in advancing our understanding of fundamental physics and unraveling the mysteries of the Universe.

arXiv:2406.07899•Frontiers in Physics•Jul 23, 2024•9 citations

Four-channel System for Characterization of Josephson Parametric Amplifiers

Boris I. Ivanov, Jinmyeong Kim, Çağlar Kutlu +8 more

The axion search experiments based on haloscopes at the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in South Korea are performed in the frequency range from 1 GHz to 6 GHz.In order to perform the experiments in a strong magnetic field of 12 T and a large-volume cavity of close to 40 liters, we use He wet dilution refrigerators with immersed superconducting magnets.The measurements require continuous operation for months without interruptions for microwave component replacements.This is achieved by using different cryogenic engineering approaches including microwave RF-switching.The critical components, defining the scanning rate and the sensitivity of the setup, are the Josephson parametric amplifiers (JPA) and cryogenic low noise amplifiers (cLNA) based on high-electron-mobility-transistor (HEMT) technology.It is desirable for both devices to have a wide frequency range and low noise close to the quantum limit for the JPA.In this paper, we show a recent design of a 4-channel measurement setup for JPA and HEMT measurements.The setup is based on a 4-channel wideband noise source (NS) and is used for both JPA and HEMT gain and noise measurements.The setup is placed at 20 mK inside the dry dilution refrigerator.The NS is thermally decoupled from the environment using plastic spacers, superconducting wires and superconducting coaxial cables.We show the gain and noise temperature curves measured for 4 HEMT amplifiers and 2 JPAs in one cool-down.

arXiv:2304.13367•International Conference on Low Temperature Physics (LT)•May 22, 2023•4 citations
We present the development of two complementary amplifier architectures for axion haloscope experiments, based on two types of Josephson Parametric Amplifiers (JPAs).The first employs a multi-chip module of flux-driven JPAs in a parallel-series configuration, enabling near quantum-limited amplification over an extended tunable range of between 1.2 and 1.5 GHz.The second design features a lumped-element JPA, offering continuous tunability across a wide frequency range from 2.4 to 4 GHz.Both approaches demonstrate near-quantum-limited noise performance and are compatible with operation in cryogenic environments.These amplifiers significantly enhance the sensitivity and frequency coverage of axion search experiments, and also provide new opportunities for broadband quantum sensing applications.
Abstract Josephson parametric amplifiers (JPAs) are used in a wide range of applications, including quantum sensing and axion dark matter searches, due to their near-quantum-limited noise performance. In this article, we present a novel amplifier configuration that increases the frequency scanning range for axion search experiments by combining six narrow-band, flux-driven JPAs. The design consists of two subsets, each comprising three JPAs connected in parallel and coupled to one of two circulators. These subsets are arranged in series. A single pump tone is split and distributed across all JPAs. We effectively mitigated challenges associated with frequency tuning and cross-talk arising from JPA band overlap while maintaining low noise performance. To validate this configuration, we implemented a JPA system spanning 1.2–1.5 GHz as the first-stage amplifier in an RF chain, where the total noise was measured to be approximately twice the standard quantum limit.
Abstract IBS/CAPP in South Korea is home to multiple active axion search experiments using cavity haloscopes that operate within the frequency range of 1-6 GHz. The haloscopes convert axions to photons, resulting in an output power of about 10-24 to 10-22 W. To detect such a small signal amidst noise, quantum-limited noise amplifiers and ultra-low-temperature environment (∼10 mK) are required for all critical read-out components to minimize noise from all of active and passive lossy components. Additionally, operating at low dissipation levels is necessary to maintain the haloscope and amplifier at a temperature of 25-40 mK. Our primary objective is to achieve the highest possible scanning-frequency speed, which includes the time for maintenance and system calibration. For the CAPP-MAX flagship experiment, we achieved a record speed of 3 MHz/day for the DFSZ-level axion sensitivity during uninterrupting measurements. This paper presents the development and operation of low-noise amplifiers for five haloscope experiments targeting different frequency ranges and provides design, operational, and performance details of the amplifiers.
Abstract The experimental non-observation of charge-parity (CP) symmetry violation in quantum chromodynamics is commonly referred to as the strong CP problem. The axion, a hypothetical elementary pseudoscalar, is expected to solve the strong CP problem and is also a promising candidate for dark matter. The most sensitive axion search experiments operate at millikelvin temperatures and hence rely on instrumentation that carries signals from a system at cryogenic temperatures to room temperature instrumentation. One of the biggest limiting factors affecting the parameter scanning speed of these detectors is the noise added by the components in the signal detection chain. Since the first amplifier in the chain limits the minimum noise, low-noise amplification is of paramount importance. This paper reports on the operation of a flux-driven Josephson parametric amplifier (JPA) operating at around 2.3 GHz with added noise approaching the quantum limit. The JPA was employed as a first stage amplifier in an experimental setting similar to the ones used in haloscope axion detectors. By operating the JPA at a gain of 19 dB and cascading it with two cryogenic amplifiers operating at 4 K, noise temperatures as low as 120 mK were achieved for the whole signal detection chain.
Abstract We present a novel amplifier configuration that combines six relatively narrow-band flux-drive Josephson Parametric Amplifiers (JPAs) to extend the bandwidth for the axion search experiments. We have addressed challenges related to the tuning and cross-talk resulting from JPA band overlap while maintaining low noise levels. Our measurements demonstrate that the added noise by an RF chain, with the JPA acting as the primary stage amplifier, remains between 75 and 175 mK from 1.19 to 1.33 GHz and from 1.36 to 1.5 GHz.
This paper provides a comprehensive overview of the development of flux-driven Josephson Parametric Amplifiers (JPAs) as Quantum Noise Limited Amplifier for axion search experiments conducted at the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science. It focuses on the characterization, and optimization of JPAs, which are crucial for achieving the highest sensitivity in axion particle detection. We discuss various characterization techniques, methods for improving bandwidth, and the attainment of ultra-low noise temperatures. JPAs have emerged as indispensable tools in CAPP’s axion search endeavors, playing a significant role in advancing our understanding of fundamental physics and unraveling the mysteries of the Universe.
The axion search experiments based on haloscopes at the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in South Korea are performed in the frequency range from 1 GHz to 6 GHz.In order to perform the experiments in a strong magnetic field of 12 T and a large-volume cavity of close to 40 liters, we use He wet dilution refrigerators with immersed superconducting magnets.The measurements require continuous operation for months without interruptions for microwave component replacements.This is achieved by using different cryogenic engineering approaches including microwave RF-switching.The critical components, defining the scanning rate and the sensitivity of the setup, are the Josephson parametric amplifiers (JPA) and cryogenic low noise amplifiers (cLNA) based on high-electron-mobility-transistor (HEMT) technology.It is desirable for both devices to have a wide frequency range and low noise close to the quantum limit for the JPA.In this paper, we show a recent design of a 4-channel measurement setup for JPA and HEMT measurements.The setup is based on a 4-channel wideband noise source (NS) and is used for both JPA and HEMT gain and noise measurements.The setup is placed at 20 mK inside the dry dilution refrigerator.The NS is thermally decoupled from the environment using plastic spacers, superconducting wires and superconducting coaxial cables.We show the gain and noise temperature curves measured for 4 HEMT amplifiers and 2 JPAs in one cool-down.