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

arXiv:2510.26749 · Applied Physics Letters

Tunable frequency conversion and comb generation with a superconducting artificial atom

F. Aziz, Zhengqi Niu, Tzu-Yen Hsieh, Kuan-Ting Lin, Y.-H. Huang, Yi‐Cheng Lin, Ching-Yeh Chen, Y.-T. Cheng, Kaun-Chun Hsieh, Jeng‐Chung Chen, Anton Frisk Kockum, Guin-Dar Lin, Zhirong Lin, P. Y. Wen, I.-C. Hoi

Published Jul 6, 2026• 0 citations
arXivHTMLPDF

Abstract

We investigate the power spectral density emitted by a superconducting artificial atom coupled to the end of a semi-infinite transmission line and driven by two continuous radio frequency fields. In this setup, we observe the generation of multiple frequency peaks and the formation of frequency combs with equal detuning between those peaks. The frequency peaks originate from wave mixing of the drive fields, mediated by the artificial atom, highlighting the potential of this system as both a frequency converter and a frequency-comb generator. We demonstrate precise control and tunability in generating these frequency features, aligning well with theoretical predictions, across a relatively wide frequency range (tens of MHz, exceeding the linewidth of the artificial atom). The extensive and simple tunability of this frequency converter and comb generator, combined with its small physical footprint, makes it promising for quantum optics on chips and other applications in quantum technology.

DOI
10.1063/5.0310058

Related papers

Controllable microwave frequency comb generation in a tunable superconducting coplanar-waveguide resonator*

Shuai-Peng Wang, Zhen Chen, Tiefu Li

Frequency combs are useful in a wide range of applications, such as optical metrology and high-precision spectroscopy. We experimentally study a controllable frequency comb generated in a tunable superconducting coplanar-waveguide resonator in the microwave regime. A two-tone drive is applied on one of the resonance modes of the resonator and comb generation is observed around the resonance frequency of the resonator. Both central frequency and teeth density of the comb are precisely controllable, and the teeth spacing can be adjusted from Hz to MHz. Moreover, we show that a few hundreds of sidebands can be generated using a sufficiently strong drive power and the weakest drive power needed to generate the comb can be reduced to approach the quantum limit. These experimental results can be qualitatively explained via theoretical analysis.

Chinese Physics B•Oct 20, 2020•10 citations

Coherent microwave comb generation via the Josephson effect

Angelo Greco, Xavier Ballu, Francesco Giazotto +1 more

Frequency combs represent exceptionally precise measurement tools due to the coherence of their spectral lines. While optical frequency comb sources constitute a well-established technology, superconducting circuits provide a relatively unexplored on-chip platform for low-dissipation comb emitters able to span from gigahertz to terahertz frequencies. We demonstrate coherent microwave frequency comb generation by leveraging the ac Josephson effect in a superconducting quantum interference device. A time-dependent magnetic drive periodically generates voltage pulses, which in the frequency domain correspond to a comb with dozens of spectral modes here reported up to mode 46. The emitted power at the device level ranges from -170 dBm to -130 dBm per harmonic, corresponding to 40 dB dynamic range in the 4-8 GHz bandwidth. The micrometer-scale footprint and minimal dissipation inherent to superconducting systems foster the integration of our comb generator with advanced cryogenic electronics. Transferring optical techniques to the solid-state domain may enable new applications in quantum technologies.

arXiv:2503.13259•Nature Communications•Feb 20, 2026•1 citation

Observation of Collapse and Revival in a Superconducting Atomic Frequency Comb

Elena S. Redchenko, Matthias Zens, Martin Žemlička +8 more

Recent advancements in superconducting circuits have enabled the experimental study of collective behavior of precisely controlled intermediate-scale ensembles of qubits. In this work, we demonstrate an atomic frequency comb formed by individual artificial atoms strongly coupled to a single resonator mode. We observe periodic microwave pulses that originate from a single coherent excitation dynamically interacting with the multiqubit ensemble. We show that this revival dynamics emerges as a consequence of the constructive and periodic rephasing of the five superconducting qubits forming the vacuum Rabi split comb. In the future, similar devices could be used as a memory with in situ tunable storage time or as an on-chip periodic pulse generator with nonclassical photon statistics.

arXiv:2310.04200•Physical Review Letters•Feb 11, 2025•6 citations

Efficient single-photon frequency conversion in the microwave domain using superconducting quantum circuits

W. Z. Jia, Y. W. Wang, Yu-xi Liu

We present an approach to achieve efficient single-photon frequency conversion in the microwave domain based on coherent control in superconducting quantum circuits, which consist of a driven artificial atom coupled to a semi-infinite transmission line. Using the full quantum-mechanical method, we analyze the single-photon scattering process in this system and find that single-photon frequency up- or down-conversion with efficiency close to unity can be achieved by adjusting the parameters of the control field applied to the artificial atom. We further show that our approach is experimentally feasible in currently available superconducting flux qubit circuits.

arXiv:1711.05153•Physical Review A•Nov 13, 2017•33 citations

Long-range entanglement and quantum correlations in a multi-frequency comb system

Sahil Pontula, Debasmita Banerjee, Marin Soljacic +1 more

Frequency combs are multimode photonic systems that underlie countless precision sensing and metrology applications. Since their invention over two decades ago, numerous efforts have pushed frequency combs to broader bandwidths and more stable operation. More recently, quantum squeezing and entanglement have been explored in single frequency comb systems for quantum advantages in sensing and signal multiplexing. However, the production of quantum light across multiple frequency combs remains unexplored. In this work, we theoretically explore a mechanism that generates a series of nonlinearly coupled frequency combs through cascaded three-wave upconversion and downconversion processes mediated by a single idler comb. We show how this system generates inter- and intracomb two-mode squeezing and entanglement spanning a very large spectral range, from ultraviolet to mid-IR frequencies. Finally, we show how this system can be engineered to produce on-demand multimode quantum light through covariance matrix optimization. Our findings could enable tunable broadband ghost spectroscopy protocols, squeezing-enhanced pump-probe measurements, and broadband entanglement between spectrally-multiplexed quanta of information.

quant-pharXiv:2511.13604•Nov 18, 2025•0 citations

Cryogenic microwave frequency combs based on quantum paraelectric superconducting resonators

Prasad Muragesh, H. Sundaresan, Madhu Thalakulam

A frequency comb, known for its precision as an “optical ruler,” features an evenly spaced spectral pattern. While these combs are vital in integrated photonics, their microwave counterparts are now highly sought in cryogenic quantum technologies, including semiconducting and superconducting qubits as well as quantum electrical metrology. However, microwave combs are still largely underexplored. Existing studies mostly rely on complex, high-power optical systems incompatible with the low-power, cryogenic on-chip architecture. In this manuscript, we present an all-electrical, on-chip, cryogenic microwave frequency comb on strontium titanate (SrTiO3), exploiting its Pockels-like effect in its quantum paraelectric phase. Our device utilizes a superconducting microwave cavity to generate the frequency comb via cavity phase modulation enabled by the field-induced effective χ(2) of SrTiO3. The ability to continuously vary the dielectric constant of SrTiO3 by the application of an electric field, in its quantum paraelectric phase, makes it possible to control the comb's operating frequency span. The exceptionally high dielectric constant of SrTiO3, > 20 000 at low temperatures, enables an ultra-miniature design and on-chip integration with cryogenic quantum technologies.

arXiv:2605.13571•Applied Physics Letters•Aug 17, 2026•0 citations
We investigate the power spectral density emitted by a superconducting artificial atom coupled to the end of a semi-infinite transmission line and driven by two continuous radio frequency fields. In this setup, we observe the generation of multiple frequency peaks and the formation of frequency combs with equal detuning between those peaks. The frequency peaks originate from wave mixing of the drive fields, mediated by the artificial atom, highlighting the potential of this system as both a frequency converter and a frequency-comb generator. We demonstrate precise control and tunability in generating these frequency features, aligning well with theoretical predictions, across a relatively wide frequency range (tens of MHz, exceeding the linewidth of the artificial atom). The extensive and simple tunability of this frequency converter and comb generator, combined with its small physical footprint, makes it promising for quantum optics on chips and other applications in quantum technology.
Frequency combs are useful in a wide range of applications, such as optical metrology and high-precision spectroscopy. We experimentally study a controllable frequency comb generated in a tunable superconducting coplanar-waveguide resonator in the microwave regime. A two-tone drive is applied on one of the resonance modes of the resonator and comb generation is observed around the resonance frequency of the resonator. Both central frequency and teeth density of the comb are precisely controllable, and the teeth spacing can be adjusted from Hz to MHz. Moreover, we show that a few hundreds of sidebands can be generated using a sufficiently strong drive power and the weakest drive power needed to generate the comb can be reduced to approach the quantum limit. These experimental results can be qualitatively explained via theoretical analysis.
Frequency combs represent exceptionally precise measurement tools due to the coherence of their spectral lines. While optical frequency comb sources constitute a well-established technology, superconducting circuits provide a relatively unexplored on-chip platform for low-dissipation comb emitters able to span from gigahertz to terahertz frequencies. We demonstrate coherent microwave frequency comb generation by leveraging the ac Josephson effect in a superconducting quantum interference device. A time-dependent magnetic drive periodically generates voltage pulses, which in the frequency domain correspond to a comb with dozens of spectral modes here reported up to mode 46. The emitted power at the device level ranges from -170 dBm to -130 dBm per harmonic, corresponding to 40 dB dynamic range in the 4-8 GHz bandwidth. The micrometer-scale footprint and minimal dissipation inherent to superconducting systems foster the integration of our comb generator with advanced cryogenic electronics. Transferring optical techniques to the solid-state domain may enable new applications in quantum technologies.
Recent advancements in superconducting circuits have enabled the experimental study of collective behavior of precisely controlled intermediate-scale ensembles of qubits. In this work, we demonstrate an atomic frequency comb formed by individual artificial atoms strongly coupled to a single resonator mode. We observe periodic microwave pulses that originate from a single coherent excitation dynamically interacting with the multiqubit ensemble. We show that this revival dynamics emerges as a consequence of the constructive and periodic rephasing of the five superconducting qubits forming the vacuum Rabi split comb. In the future, similar devices could be used as a memory with in situ tunable storage time or as an on-chip periodic pulse generator with nonclassical photon statistics.
We present an approach to achieve efficient single-photon frequency conversion in the microwave domain based on coherent control in superconducting quantum circuits, which consist of a driven artificial atom coupled to a semi-infinite transmission line. Using the full quantum-mechanical method, we analyze the single-photon scattering process in this system and find that single-photon frequency up- or down-conversion with efficiency close to unity can be achieved by adjusting the parameters of the control field applied to the artificial atom. We further show that our approach is experimentally feasible in currently available superconducting flux qubit circuits.
Frequency combs are multimode photonic systems that underlie countless precision sensing and metrology applications. Since their invention over two decades ago, numerous efforts have pushed frequency combs to broader bandwidths and more stable operation. More recently, quantum squeezing and entanglement have been explored in single frequency comb systems for quantum advantages in sensing and signal multiplexing. However, the production of quantum light across multiple frequency combs remains unexplored. In this work, we theoretically explore a mechanism that generates a series of nonlinearly coupled frequency combs through cascaded three-wave upconversion and downconversion processes mediated by a single idler comb. We show how this system generates inter- and intracomb two-mode squeezing and entanglement spanning a very large spectral range, from ultraviolet to mid-IR frequencies. Finally, we show how this system can be engineered to produce on-demand multimode quantum light through covariance matrix optimization. Our findings could enable tunable broadband ghost spectroscopy protocols, squeezing-enhanced pump-probe measurements, and broadband entanglement between spectrally-multiplexed quanta of information.
A frequency comb, known for its precision as an “optical ruler,” features an evenly spaced spectral pattern. While these combs are vital in integrated photonics, their microwave counterparts are now highly sought in cryogenic quantum technologies, including semiconducting and superconducting qubits as well as quantum electrical metrology. However, microwave combs are still largely underexplored. Existing studies mostly rely on complex, high-power optical systems incompatible with the low-power, cryogenic on-chip architecture. In this manuscript, we present an all-electrical, on-chip, cryogenic microwave frequency comb on strontium titanate (SrTiO3), exploiting its Pockels-like effect in its quantum paraelectric phase. Our device utilizes a superconducting microwave cavity to generate the frequency comb via cavity phase modulation enabled by the field-induced effective χ(2) of SrTiO3. The ability to continuously vary the dielectric constant of SrTiO3 by the application of an electric field, in its quantum paraelectric phase, makes it possible to control the comb's operating frequency span. The exceptionally high dielectric constant of SrTiO3, > 20 000 at low temperatures, enables an ultra-miniature design and on-chip integration with cryogenic quantum technologies.