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

Quantum cryptographic protocol implementation using a highly-efficient cold-atom-based quantum memory

Hadriel Mamann, Thomas Nieddu, Mathieu Bozzio, Félix Hoffet, Félix Garreau de Loubresse, Eleni Diamanti, Alban Urvoy, Julien Laurat

Published Jan 1, 2023• 1 citation
Publisher

Abstract

We report on a highly-efficient cold-atom-based quantum memory and its use to perform a quantum money protocol. We also simulate the multi-mode capacity of this quantum memory using Hermite-Gaussian modes of light.
DOI
10.1364/cleo_fs.2023.ff2a.3

Related papers

Combining a quantum cryptographic protocol with a highly efficient cold-atom-based quantum memory

Félix Garreau de Loubresse, Hadriel Mamann, Thomas Nieddu +6 more

We report the first demonstration of a quantum cryptographic protocol incorporating a quantum memory layer. The protocol imposes strigent requirements on the memory storage-and-retrieval efficiency and on the error rate of the communication.

Quantum 2.0 Conference and Exhibition•Jan 1, 2025•0 citations

Cold-atomic ensemble implemented as an efficient optical quantum memory layer in a cryptographic protocol

Hadriel Mamann

Combining cryptographic protocols with quantum memories is an important step for quantum network development in order to establish secure communications where information can be stored and retrieved on demand. One possible use case of these networks is to perform authenticated transactions synchronized by the use of memories. However, the losses and noise added by storage devices can be exploited by dishonest agents to hide their cheating attempts. The constraints to operate in a secure regime are thus very demanding in terms of memory efficiency and fidelity. This thesis focuses on the implementation of a cold-atomic ensemble used as an EIT-based quantum memory in a cryptographic protocol. The key ingredients to optimize the storage-and-retrieval efficiency and the method employed to mitigate the decoherence sources are detailed. This work reports the first demonstration of the unforgeable quantum money including an intermediate quantum memory layer, taking advantage of our highly-efficient and low-noise storage platform. The next step would be to spatially multiplex the atomic cloud in order to store the whole sequence of random qubits at once. In this scenario, the multimode capacity of our memory has been numerically simulated using two different spatial multiplexing techniques.

•May 17, 2024•0 citations

Quantum cryptography integrating an optical quantum memory

Hadriel Mamann, Thomas Nieddu, Félix Hoffet +6 more

Developments in scalable quantum networks rely critically on optical quantum memories, which are key components enabling the storage of quantum information. These memories play a pivotal role for entanglement distribution and long-distance quantum communication, with remarkable advances achieved in this context. However, optical memories have broader applications, and their storage and buffering capabilities can benefit a wide range of future quantum technologies. Here, we present the demonstration of a cryptography protocol incorporating an intermediate quantum memory layer. Specifically, we implement Wiesner's unforgeable quantum money primitive with a storage step, rather than as an on-the-fly procedure. This protocol imposes stringent requirements on storage efficiency and noise level to reach a secure regime. We demonstrate the implementation with polarization encoding of weak coherent states of light and a high-efficiency cold atom-based quantum memory and validate the full scheme. Our results showcase a major capability, opening broader avenues for quantum memory utilization and network functionalities.

arXiv:2504.00094•Science Advances•Sep 19, 2025•12 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

Multiplexed Quantum Memory with Many Functions: Entanglement Generation and Interferometric Processing

Michal P. Parniak, Mateusz Mazelanik, Adam Leszczyński +2 more

We present an optical quantum memory based on cold rubidium atoms that can generate and process quantum states of light. The multimode capacity of the memory enables enhanced implementation of protocols.

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)•Jul 31, 2022•0 citations

Multiplexed quantum memory with many functions: entanglement generation and interferometric processing

Michal P. Parniak, Mateusz Mazelanik, Adam Leszczyński +2 more

We present an optical quantum memory based on cold rubidium atoms that can generate and process quantum states of light. The multimode capacity of the memory enables enhanced implementation of protocols.

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)•Jan 1, 2022•0 citations
Combining cryptographic protocols with quantum memories is an important step for quantum network development in order to establish secure communications where information can be stored and retrieved on demand. One possible use case of these networks is to perform authenticated transactions synchronized by the use of memories. However, the losses and noise added by storage devices can be exploited by dishonest agents to hide their cheating attempts. The constraints to operate in a secure regime are thus very demanding in terms of memory efficiency and fidelity. This thesis focuses on the implementation of a cold-atomic ensemble used as an EIT-based quantum memory in a cryptographic protocol. The key ingredients to optimize the storage-and-retrieval efficiency and the method employed to mitigate the decoherence sources are detailed. This work reports the first demonstration of the unforgeable quantum money including an intermediate quantum memory layer, taking advantage of our highly-efficient and low-noise storage platform. The next step would be to spatially multiplex the atomic cloud in order to store the whole sequence of random qubits at once. In this scenario, the multimode capacity of our memory has been numerically simulated using two different spatial multiplexing techniques.
Developments in scalable quantum networks rely critically on optical quantum memories, which are key components enabling the storage of quantum information. These memories play a pivotal role for entanglement distribution and long-distance quantum communication, with remarkable advances achieved in this context. However, optical memories have broader applications, and their storage and buffering capabilities can benefit a wide range of future quantum technologies. Here, we present the demonstration of a cryptography protocol incorporating an intermediate quantum memory layer. Specifically, we implement Wiesner's unforgeable quantum money primitive with a storage step, rather than as an on-the-fly procedure. This protocol imposes stringent requirements on storage efficiency and noise level to reach a secure regime. We demonstrate the implementation with polarization encoding of weak coherent states of light and a high-efficiency cold atom-based quantum memory and validate the full scheme. Our results showcase a major capability, opening broader avenues for quantum memory utilization and network functionalities.
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.