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

Acta Physica Sinica

Research progress of superconductor and cold atoms hybrid quantum system

Qing-Xian Lv, Sai Li, Hai-Tao Tu, Kai-Yu Liao, Zhen-Tao Liang, Hui Yan, Shi-Liang Zhu

Published Jan 1, 2023• 1 citation
Publisher

Abstract

The hybrid quantum system composed of superconductor and cold atoms is expected to achieve fast quantum gates, long-life quantum storage and long-distance transmission through optical fibers, making it one of the most promising hybrid quantum systems to realize optical interconnection between two superconducting quantum computers. In this paper, we comprehensively review the recent research advancements in the optical interconnection of two superconducting quantum computers, based on the superconductor and cold atoms hybrid quantum system, specifically the review covers the coherent coupling between superconducting chips and cold atoms, the coherent microwave-to-optics conversion, and the long-range microwave interconnection between superconducting qubits and quantum converters. The system is expected to provide a physical and technical foundation for practical optical-fiber interconnection of two superconducting quantum computers, and have broad applications in distributed superconducting quantum computation and hybrid quantum networks.

DOI
10.7498/aps.72.20230985

Related papers

Towards integrated microwave-to-optical conversion by atoms on a superconducting chip

Jean-Baptiste Gérent, Romain Veyron, Vincent Mançois +1 more

The coherent conversion of microwave to optical signals is for now a missing hardware for long-distance quantum communication between superconducting quantum (sub)processors that could form the nodes of a future quantum network. Various architectures for quantum simulations and information processing are being currently explored with different TRL levels. Among these, circuits of superconducting qubits have already moved from the fundamental research environment to the R&D units of companies. Recent developments have shown extraordinary abilities for performing fast and high-fidelity quantum logic operations. Their limitations are short coherence times precluding long-term storage of quantum information, and the difficulty of coupling distant quantum registers using microwave photons that are (near)resonant with qubit transitions. There is thus a need for (i) a quantum memory compatible with superconducting qubits, and (ii) a microwave to optical transducer to demonstrate the complete communication protocol between distant sub-registers consisting of a moderate number of superconducting qubits. Cold alkaline atoms which have long coherence time and possess transitions both in the MW and optical domain could certainly help improve on these limitations. In this presentation, I will describe how an integrated atom chip compatible with superconducting quantum processors and optical communication networks will be realized within the newly funded MOCA consortium that received the support from the QuantERA ERA-NET Cofund. I will also specifically discuss a newly developed solution to transport atoms in the near field of surfaces were the atom-light coupling strength will be enhanced.

•Sep 1, 2022•0 citations

A hybrid quantum system of atoms trapped on ultrathin optical fibers coupled to superconductors

S. L. Rolston, J. R. Anderson, U. Chukwu +14 more

Hybrid quantum systems can be formed that combine the strengths of multiple platforms while avoiding the weaknesses. Here we report on progress toward a hybrid quantum system of neutral atom spins coupled to superconducting qubits. We trap laser-cooled rubidium atoms in the evanescent field of an ultrathin optical fiber, which will be suspended a few microns above a superconducting circuit that resonates at the hyperfine frequency of the Rb atoms, allowing magnetic coupling between the atoms and superconductor. As this will be done in a dilution refrigerator environment, the technical demands on the optical fiber is severe. We have developed and optimized a tapered fiber fabrication system, achieving optical transmission in excess of 99.95% , and fibers that can sustain 400 mW of optical power in a UHV environment. We have also optimized tapered fibers that can support higher order optical modes with high transmission (> 97%), which may be useful for different optical potential geometries. We have developed an in-situ tunable high-Q superconducting microwave resonator that can be tuned to within the resonator linewidth of the 6.8 GHz frequency of the Rb hyperfine transition.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 26, 2013•4 citations

Hybrid superconductor-semiconductor systems for quantum technology

M. Benito, Guido Burkard

Superconducting quantum devices provide excellent connectivity and controllability, while semiconductor spin qubits stand out with their long-lasting quantum coherence, fast control, and potential for miniaturization and scaling. In the last few years, remarkable progress has been made in combining superconducting circuits and semiconducting devices into hybrid quantum systems that benefit from the physical properties of both constituents. Superconducting cavities can mediate quantum-coherent coupling over long distances between electronic degrees of freedom such as the spin of individual electrons on a semiconductor chip and, thus, provide essential connectivity for a quantum device. Electron spins in semiconductor quantum dots have reached very long coherence times and allow for fast quantum gate operations with increasing fidelities. We summarize recent progress and theoretical models that describe superconducting–semiconducting hybrid quantum systems, explain the limitations of these systems, and describe different directions where future experiments and theory are headed.

arXiv:2005.00030•Applied Physics Letters•May 11, 2020•35 citations

Superconducting atom chips: towards quantum hybridization

Rainer Dumke, Deshui Yu, Christoph Hufnagel +2 more

Atomic-superconducting hybrid systems are of particular interest as they are combining the long coherence times of ultracold atoms and fast gate operation times of superconducting circuits. Here we discuss an experimental realization of an interface between cold Rydberg atoms and a transmon circuit embedded in a microwave cavity. We present numerical calculations showing a significant coupling of Rydberg atoms to a transmon. Here we place the atoms in the vicinity of the transmon shunting capacitor. Exciting them to the Rydberg states alters the dielectric constant of the medium inside the capacitor. This results in a dispersive shift of the transmon resonance frequency. Using the protocols developed in Ref. 1, 2 will allow the coherent transfer of quantum states between these two systems.

Quantum Photonic Devices•Aug 29, 2017•3 citations

Interfacing Superconducting Qubits with Light

Piero Chiappina

Superconducting quantum circuits are a leading hardware candidate for realizing a large-scale fault-tolerant quantum computer. However, scaling superconducting quantum computers will soon approach the physical limits imposed by their cryogenic operating environments. Consequently, interconnects between multiple processor modules will become increasingly necessary for scaling quantum computers. Optical fiber is a particularly promising candidate for these interconnects due to its low loss and negligible thermal noise at room temperature. However, interfacing microwave-frequency superconducting circuits with optical fibers presents several challenges. In this thesis, we present a modular architecture which addresses many of the current challenges in building this interface. We develop an optomechanical quantum transducer which is capable of generating microwave- and optical-frequency photons in pairs, and demonstrate quantum entanglement between these microwave-optical photon pairs. Further, we develop a superconducting qubit module optimized for efficient absorption of itinerant microwave photons, and demonstrate a high-efficiency photon catch protocol. Finally, we connect the superconducting qubit module to the transducer module via a superconducting microwave cable. We drive the microwave-optical photon pair generation process in the transducer module and employ the photon catch protocol in the qubit module to facilitate state transfer between the qubit and the flying microwave photon from the transducer. We observe correlations between the final qubit state and the detection of an optical photon, demonstrating a crucial step toward establishing quantum entanglement between superconducting qubits and light. We discuss ongoing progress and challenges in realizing hybrid entanglement and in extending this approach to entangle remote superconducting qubits over optical networks.

•Aug 19, 2026•0 citations

Novel qubits in hybrid semiconductor-superconductor nanostructures

Marta Pita-Vidal, Rubén Seoane Souto, Srijit Goswami +4 more

Hybrid semiconductor-superconductor qubits have recently emerged as a promising alternative to traditional platforms, combining material advantages with device-level tunability. A defining feature is their gate-tunable Josephson coupling, enabling superconducting qubit architectures with full electric-field control and offering a path toward scalable, low-crosstalk quantum processors. This approach seeks to merge benefits of superconducting and semiconductor qubits, for instance by encoding quantum information in the spin of a quasiparticle occupying an Andreev bound state, thus combining long coherence times with fast, flexible control. Progress has accelerated through bottom-up engineering of Andreev states in coupled quantum dot arrays, leading to architectures such as minimal Kitaev chains hosting Majorana zero modes. In parallel, Hamiltonian-protected designs aim to enhance resilience against local noise and decoherence by exploiting superconducting phase dynamics and discrete charge or flux degrees of freedom. This article reviews recent theoretical and experimental advances in hybrid qubits, providing an overview of physical mechanisms, device implementations, and emerging architectures, with emphasis on their potential for (topologically) protected quantum information processing. While many designs remain at proof-of-concept stage, rapid progress suggests practical demonstrations may soon be achievable.

cond-mat.mes-hallCross-listedarXiv:2512.23336•Dec 30, 2025•1 citation
The hybrid quantum system composed of superconductor and cold atoms is expected to achieve fast quantum gates, long-life quantum storage and long-distance transmission through optical fibers, making it one of the most promising hybrid quantum systems to realize optical interconnection between two superconducting quantum computers. In this paper, we comprehensively review the recent research advancements in the optical interconnection of two superconducting quantum computers, based on the superconductor and cold atoms hybrid quantum system, specifically the review covers the coherent coupling between superconducting chips and cold atoms, the coherent microwave-to-optics conversion, and the long-range microwave interconnection between superconducting qubits and quantum converters. The system is expected to provide a physical and technical foundation for practical optical-fiber interconnection of two superconducting quantum computers, and have broad applications in distributed superconducting quantum computation and hybrid quantum networks.
The coherent conversion of microwave to optical signals is for now a missing hardware for long-distance quantum communication between superconducting quantum (sub)processors that could form the nodes of a future quantum network. Various architectures for quantum simulations and information processing are being currently explored with different TRL levels. Among these, circuits of superconducting qubits have already moved from the fundamental research environment to the R&D units of companies. Recent developments have shown extraordinary abilities for performing fast and high-fidelity quantum logic operations. Their limitations are short coherence times precluding long-term storage of quantum information, and the difficulty of coupling distant quantum registers using microwave photons that are (near)resonant with qubit transitions. There is thus a need for (i) a quantum memory compatible with superconducting qubits, and (ii) a microwave to optical transducer to demonstrate the complete communication protocol between distant sub-registers consisting of a moderate number of superconducting qubits. Cold alkaline atoms which have long coherence time and possess transitions both in the MW and optical domain could certainly help improve on these limitations. In this presentation, I will describe how an integrated atom chip compatible with superconducting quantum processors and optical communication networks will be realized within the newly funded MOCA consortium that received the support from the QuantERA ERA-NET Cofund. I will also specifically discuss a newly developed solution to transport atoms in the near field of surfaces were the atom-light coupling strength will be enhanced.
Hybrid quantum systems can be formed that combine the strengths of multiple platforms while avoiding the weaknesses. Here we report on progress toward a hybrid quantum system of neutral atom spins coupled to superconducting qubits. We trap laser-cooled rubidium atoms in the evanescent field of an ultrathin optical fiber, which will be suspended a few microns above a superconducting circuit that resonates at the hyperfine frequency of the Rb atoms, allowing magnetic coupling between the atoms and superconductor. As this will be done in a dilution refrigerator environment, the technical demands on the optical fiber is severe. We have developed and optimized a tapered fiber fabrication system, achieving optical transmission in excess of 99.95% , and fibers that can sustain 400 mW of optical power in a UHV environment. We have also optimized tapered fibers that can support higher order optical modes with high transmission (> 97%), which may be useful for different optical potential geometries. We have developed an in-situ tunable high-Q superconducting microwave resonator that can be tuned to within the resonator linewidth of the 6.8 GHz frequency of the Rb hyperfine transition.
Superconducting quantum devices provide excellent connectivity and controllability, while semiconductor spin qubits stand out with their long-lasting quantum coherence, fast control, and potential for miniaturization and scaling. In the last few years, remarkable progress has been made in combining superconducting circuits and semiconducting devices into hybrid quantum systems that benefit from the physical properties of both constituents. Superconducting cavities can mediate quantum-coherent coupling over long distances between electronic degrees of freedom such as the spin of individual electrons on a semiconductor chip and, thus, provide essential connectivity for a quantum device. Electron spins in semiconductor quantum dots have reached very long coherence times and allow for fast quantum gate operations with increasing fidelities. We summarize recent progress and theoretical models that describe superconducting–semiconducting hybrid quantum systems, explain the limitations of these systems, and describe different directions where future experiments and theory are headed.
Atomic-superconducting hybrid systems are of particular interest as they are combining the long coherence times of ultracold atoms and fast gate operation times of superconducting circuits. Here we discuss an experimental realization of an interface between cold Rydberg atoms and a transmon circuit embedded in a microwave cavity. We present numerical calculations showing a significant coupling of Rydberg atoms to a transmon. Here we place the atoms in the vicinity of the transmon shunting capacitor. Exciting them to the Rydberg states alters the dielectric constant of the medium inside the capacitor. This results in a dispersive shift of the transmon resonance frequency. Using the protocols developed in Ref. 1, 2 will allow the coherent transfer of quantum states between these two systems.
Superconducting quantum circuits are a leading hardware candidate for realizing a large-scale fault-tolerant quantum computer. However, scaling superconducting quantum computers will soon approach the physical limits imposed by their cryogenic operating environments. Consequently, interconnects between multiple processor modules will become increasingly necessary for scaling quantum computers. Optical fiber is a particularly promising candidate for these interconnects due to its low loss and negligible thermal noise at room temperature. However, interfacing microwave-frequency superconducting circuits with optical fibers presents several challenges. In this thesis, we present a modular architecture which addresses many of the current challenges in building this interface. We develop an optomechanical quantum transducer which is capable of generating microwave- and optical-frequency photons in pairs, and demonstrate quantum entanglement between these microwave-optical photon pairs. Further, we develop a superconducting qubit module optimized for efficient absorption of itinerant microwave photons, and demonstrate a high-efficiency photon catch protocol. Finally, we connect the superconducting qubit module to the transducer module via a superconducting microwave cable. We drive the microwave-optical photon pair generation process in the transducer module and employ the photon catch protocol in the qubit module to facilitate state transfer between the qubit and the flying microwave photon from the transducer. We observe correlations between the final qubit state and the detection of an optical photon, demonstrating a crucial step toward establishing quantum entanglement between superconducting qubits and light. We discuss ongoing progress and challenges in realizing hybrid entanglement and in extending this approach to entangle remote superconducting qubits over optical networks.
Hybrid semiconductor-superconductor qubits have recently emerged as a promising alternative to traditional platforms, combining material advantages with device-level tunability. A defining feature is their gate-tunable Josephson coupling, enabling superconducting qubit architectures with full electric-field control and offering a path toward scalable, low-crosstalk quantum processors. This approach seeks to merge benefits of superconducting and semiconductor qubits, for instance by encoding quantum information in the spin of a quasiparticle occupying an Andreev bound state, thus combining long coherence times with fast, flexible control. Progress has accelerated through bottom-up engineering of Andreev states in coupled quantum dot arrays, leading to architectures such as minimal Kitaev chains hosting Majorana zero modes. In parallel, Hamiltonian-protected designs aim to enhance resilience against local noise and decoherence by exploiting superconducting phase dynamics and discrete charge or flux degrees of freedom. This article reviews recent theoretical and experimental advances in hybrid qubits, providing an overview of physical mechanisms, device implementations, and emerging architectures, with emphasis on their potential for (topologically) protected quantum information processing. While many designs remain at proof-of-concept stage, rapid progress suggests practical demonstrations may soon be achievable.