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

Science

Efficient transfer of entanglement

Ian S. Osborne

Published Nov 5, 2020• 0 citations
Publisher

Abstract

Quantum Systems Processing quantum information across a network relies on the encoding, storage, manipulation, and transfer of quantum states between the nodes along the network chain. However, the information stored in the fragile quantum states can be lost as they propagate along the network, limiting the overall transfer efficiency typically to between 15 and 20% and thereby compromising the scalability of the network. Cao et al. developed a method to enhance the efficiency with which the quantum information can be transferred. Using temporally shaped single-photon light pulses and a cold atom storage medium, their protocol can enhance the storage and retrieval efficiency to ∼85%. Further improvement in the transfer efficiency of entanglement between the quantum memories and the information carrier (photons) will advance the development of quantum communication technologies. Optica 7 , 1440 (2020).

DOI
10.1126/science.370.6517.678-f

Related papers

Efficient reversible entanglement transfer between light and quantum memories

Mingtao Cao, Félix Hoffet, Shuwei Qiu +2 more

Reversible entanglement transfer between light and matter is a crucial requisite for the ongoing developments of quantum information technologies. Quantum networks and their envisioned applications, e.g., secure communications beyond direct transmission, distributed quantum computing, or enhanced sensing, rely on entanglement distribution between nodes. Although entanglement transfer has been demonstrated, a current roadblock is the limited efficiency of this process that can compromise the scalability of multi-step architectures. Here we demonstrate the efficient transfer of heralded single-photon entanglement into and out of two quantum memories based on large ensembles of cold cesium atoms. We achieve an overall storage-and-retrieval efficiency of 85% together with a preserved suppression of the two-photon component of about 10% of the value for a coherent state. Our work constitutes an important capability that is needed toward large scale networks and increased functionality.

arXiv:2007.00022•Optica•Sep 10, 2020•95 citations

Combining Quantum Cryptographic Primitives with Highly-Efficient Cold-Atom-Based Quantum Memory

Hadriel Mamann, Thomas Nieddu, Mathieu Bozzio +5 more

In order to build long-distance quantum communications, quantum memories are required as a synchronization tool which allows entanglement to be stored and retrieved on-demand, when the system is ready to perform entanglement swapping [1]. The storage-and-retrieval efficiency is a key parameter: an increase from 60% to 90% drastically decreases, typically by 2 orders of magnitude, the average time for entanglement distribution over a distance of 600 kilometers. Within this context, we reported quantum transfer between light and cold-atom-based quantum memory featuring a single mode storage-and-retrieval efficiency as high as 87%(±5%), in the single excitation regime [2]. Moreover, we demonstrated the storage of single-photon entanglement into two memories, with a ratio of the input and output concurrences reaching 88%, a more than three-fold increase compared to prior works (Fig. 1). The demonstrated capability required operating at a very large optical depth (OD) of the atomic ensembles on the$D_{1}$line of cesium, and with a strong and preserved suppression of the two-photon component.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 26, 2023•0 citations

Highly-efficient entanglement storage of light in cold-atom quantum memories

Félix Hoffet, Mingtao Cao, Shuwei Qiu +4 more

Highly-efficient entanglement storage in quantum memories is a critical requirement for quantum networks. We present an experiment where we stored single-photon entanglement into two atomic-ensemble based quantum memories with an overall efficiency of 87%.

Conference on Lasers and Electro-Optics•Jan 1, 2021•1 citation

**Quantum Entanglement-Based Distributed Memory**

Jincheng Zhang

This paper proposes a novel approach to distributed memory leveraging the unique properties of quantum entanglement. The core claim is that entanglement can enable long-range, low-latency, and high-capacity distributed memory, effectively bypassing the limitations of traditional network-based data transfer. The proposed mechanism involves a distributed storage system built upon Quantum Key Distribution (QKD) principles. Each node in the system stores a portion of the overall data, and entanglement between quantum bits (qubits) is utilized to establish correlations. By performing measurements and operations on these entangled states, data access and updates can be achieved rapidly and securely across geographically separated nodes. This work addresses the significant challenges inherent in maintaining high-fidelity entanglement and developing efficient entanglement manipulation protocols for large-scale quantum networks. The theoretical framework presented here outlines a foundational architecture for this emerging technology.

•Aug 31, 2026•0 citations

Quantum Communication between Multiplexed Atomic Quantum Memories

Chang Li, Nan Jiang, Yukai Wu +4 more

The use of multiplexed atomic quantum memories (MAQM) can significantly enhance the efficiency to establish entanglement in a quantum network. In the previous experiments, individual elements of a quantum network, such as the generation, storage, and transmission of quantum entanglement have been demonstrated separately. Here we report an experiment to show the compatibility and integration of these basic operations. Specifically, we generate photon-atom entanglement from any chosen pair of memory cells in a 6×5 MAQM, convert the spin-wave to time-bin photonic excitation after a controllable storage time, and then store and retrieve the photon in a second MAQM for another controllable storage time. The preservation of quantum information in this process is verified by measuring the state fidelity. We also demonstrate that higher dimension quantum states can be transferred between the two distant MAQMs.

arXiv:1909.02185•Physical Review Letters•Jun 19, 2020•30 citations

Title: Quantum Entanglement Network Propagation for Information Transfer

Jincheng Zhang

Quantum entanglement, a cornerstone of quantum mechanics, offers the potential for unparalleled information transfer capabilities. However, maintaining and extending entanglement over long distances presents a significant challenge. This paper explores a novel protocol for quantum entanglement propagation, designed to optimize for speed and fidelity of information transfer through the implementation of a dynamically-adjusted entanglement network. We introduce a mechanism that facilitates the propagation of entanglement through a network, increasing the rate of information transfer compared to traditional methods. This work addresses the fundamental limitations of existing approaches and lays the groundwork for a robust and scalable quantum information network. The proposed protocol employs a hierarchical network structure and incorporates adaptive entanglement distribution strategies to enhance robustness and efficiency. We present a detailed mathematical framework, including key operational parameters and performance metrics, demonstrating the efficacy of our approach in a simulated environment. The resulting network demonstrates a significant improvement in information transfer rate and fidelity compared to baseline models. This research contributes to the advancement of quantum communication and information processing technologies.

•Sep 3, 2026•0 citations
Quantum Systems
Processing quantum information across a network relies on the encoding, storage, manipulation, and transfer of quantum states between the nodes along the network chain. However, the information stored in the fragile quantum states can be lost as they propagate along the network, limiting the overall transfer efficiency typically to between 15 and 20% and thereby compromising the scalability of the network. Cao et al. developed a method to enhance the efficiency with which the quantum information can be transferred. Using temporally shaped single-photon light pulses and a cold atom storage medium, their protocol can enhance the storage and retrieval efficiency to ∼85%. Further improvement in the transfer efficiency of entanglement between the quantum memories and the information carrier (photons) will advance the development of quantum communication technologies.
Optica 7 , 1440 (2020).
Reversible entanglement transfer between light and matter is a crucial requisite for the ongoing developments of quantum information technologies. Quantum networks and their envisioned applications, e.g., secure communications beyond direct transmission, distributed quantum computing, or enhanced sensing, rely on entanglement distribution between nodes. Although entanglement transfer has been demonstrated, a current roadblock is the limited efficiency of this process that can compromise the scalability of multi-step architectures. Here we demonstrate the efficient transfer of heralded single-photon entanglement into and out of two quantum memories based on large ensembles of cold cesium atoms. We achieve an overall storage-and-retrieval efficiency of 85% together with a preserved suppression of the two-photon component of about 10% of the value for a coherent state. Our work constitutes an important capability that is needed toward large scale networks and increased functionality.
In order to build long-distance quantum communications, quantum memories are required as a synchronization tool which allows entanglement to be stored and retrieved on-demand, when the system is ready to perform entanglement swapping [1]. The storage-and-retrieval efficiency is a key parameter: an increase from 60% to 90% drastically decreases, typically by 2 orders of magnitude, the average time for entanglement distribution over a distance of 600 kilometers. Within this context, we reported quantum transfer between light and cold-atom-based quantum memory featuring a single mode storage-and-retrieval efficiency as high as 87%(±5%), in the single excitation regime [2]. Moreover, we demonstrated the storage of single-photon entanglement into two memories, with a ratio of the input and output concurrences reaching 88%, a more than three-fold increase compared to prior works (Fig. 1). The demonstrated capability required operating at a very large optical depth (OD) of the atomic ensembles on theD1D_{1}D1​line of cesium, and with a strong and preserved suppression of the two-photon component.
This paper proposes a novel approach to distributed memory leveraging the unique properties of quantum entanglement. The core claim is that entanglement can enable long-range, low-latency, and high-capacity distributed memory, effectively bypassing the limitations of traditional network-based data transfer. The proposed mechanism involves a distributed storage system built upon Quantum Key Distribution (QKD) principles. Each node in the system stores a portion of the overall data, and entanglement between quantum bits (qubits) is utilized to establish correlations. By performing measurements and operations on these entangled states, data access and updates can be achieved rapidly and securely across geographically separated nodes. This work addresses the significant challenges inherent in maintaining high-fidelity entanglement and developing efficient entanglement manipulation protocols for large-scale quantum networks. The theoretical framework presented here outlines a foundational architecture for this emerging technology.
The use of multiplexed atomic quantum memories (MAQM) can significantly enhance the efficiency to establish entanglement in a quantum network. In the previous experiments, individual elements of a quantum network, such as the generation, storage, and transmission of quantum entanglement have been demonstrated separately. Here we report an experiment to show the compatibility and integration of these basic operations. Specifically, we generate photon-atom entanglement from any chosen pair of memory cells in a 6×5 MAQM, convert the spin-wave to time-bin photonic excitation after a controllable storage time, and then store and retrieve the photon in a second MAQM for another controllable storage time. The preservation of quantum information in this process is verified by measuring the state fidelity. We also demonstrate that higher dimension quantum states can be transferred between the two distant MAQMs.
Quantum entanglement, a cornerstone of quantum mechanics, offers the potential for unparalleled information transfer capabilities. However, maintaining and extending entanglement over long distances presents a significant challenge. This paper explores a novel protocol for quantum entanglement propagation, designed to optimize for speed and fidelity of information transfer through the implementation of a dynamically-adjusted entanglement network. We introduce a mechanism that facilitates the propagation of entanglement through a network, increasing the rate of information transfer compared to traditional methods. This work addresses the fundamental limitations of existing approaches and lays the groundwork for a robust and scalable quantum information network. The proposed protocol employs a hierarchical network structure and incorporates adaptive entanglement distribution strategies to enhance robustness and efficiency. We present a detailed mathematical framework, including key operational parameters and performance metrics, demonstrating the efficacy of our approach in a simulated environment. The resulting network demonstrates a significant improvement in information transfer rate and fidelity compared to baseline models. This research contributes to the advancement of quantum communication and information processing technologies.