Satellite-based quantum information networks: use cases, architecture, and roadmap
Laurent de Forges de Parny, Olivier Alibart, Julien Debaud, Sacha Gressani, Alek Lagarrigue, Anthony Martin, Alexandre Metrat, Matteo Schiavon, Tess Troisi, Eleni Diamanti, Patrick Gélard, Erik R. T. Kerstel, Sébastien Tanzilli, Mathias van den Bossche
Abstract Quantum Information Networks (QINs) attract increasing interest, as they enable connecting quantum devices over long distances, thus greatly enhancing their intrinsic computing, sensing, and security capabilities. The core mechanism of a QIN is quantum state teleportation, consuming quantum entanglement, which can be seen in this context as a new kind of network resource. Here we identify use cases per activity sector, including key performance targets, as a reference for the network requirements. We then define a high-level architecture of a generic QIN, before focusing on the architecture of the Space segment, with the aim of identifying the main design drivers and critical elements. A survey of the state-of-the-art of these critical elements is presented, as are issues related to standardisation. Finally, we explain our roadmap to developing the first QINs and detail the already concluded first step, the design and numerical simulation of a Space-to-ground entanglement distribution demonstrator.
Abstract Quantum Information Networks (QINs) attract increasing interest, as they enable connecting quantum devices over long distances, thus greatly enhancing their intrinsic computing, sensing, and security capabilities. The core mechanism of a QIN is quantum state teleportation, consuming quantum entanglement, which can be seen in this context as a new kind of network resource. Here we identify use cases per activity sector, including key performance targets, as a reference for the network requirements. We then define a high-level architecture of a generic QIN, before focusing on the architecture of the Space segment, with the aim of identifying the main design drivers and critical elements. A survey of the state-of-the-art of these critical elements is presented, as are issues related to standardisation. Finally, we explain our roadmap to developing the first QINs and detail the already concluded first step, the design and numerical simulation of a Space-to-ground entanglement distribution demonstrator.
Quantum Information Networks (QIN) attract increasing interest, as they will enable interconnection of multiple quantum devices in a distributed organization thus enhancing intrinsic computing, sensing, and security capabilities. The core mechanism of a QIN is quantum state swapping, based on teleportation, which consumes quantum entanglement, and which can be seen in this context as a new kind of network resource. The satellite is expected to play a central role for supporting global connectivity in such novel networks in which ground fiber links have stringent restrictions in length due to the absorption losses in optical fibers. There is indeed fundamental limits in the maximal fiber links distance which may not be exceeded for any unitary links. In this paper we clarify our motivations to develop such networks with satellites, and we discuss their associated use cases based on entanglement distribution, and we present the future potential users. We also assess quantitatively the ranges for which the satellite becomes mandatory in quantum information networks.
Quantum Information networks (QIN) aim to interconnect quantum systems via quantum repeaters through end-to-end entanglement of qubits. The integration of both satellites and ground segments is essential to provide global connectivity, even over large distances. In this paper, we study the problem of entanglement routing in large-scale quantum networks -i.e., with a large number of nodes, with a hybrid space-ground architecture. We decompose the routing problem into two subcomponents: request scheduling and path selection, and structure our approach around two phases: a proactive and a reactive step. We design and implement an entanglement routing strategy in an emulated European quantum network, first in a custom Python-based simulator for performance forecasting, and then into the NetSquid quantum network simulator. Our work thus provides a tool allowing for a comparison between terrestrial and satellite segments in terms of successful end-to-end entanglement in a large-scale network and shows that both segments are required for optimal service. Our results indicate that, within the emulated European topology, terrestrial networks can support end-toend entanglement for approximately 35% of user pairs -the remaining pairs are too distant and suffer from prohibitive losses. In contrast, the satellite-based network achieves connectivity for up to 91% of user pairs, although some pairs remain unreachable due to a lack of simultaneous satellite visibility. However, while satellites can outperform terrestrial networks in total photon distribution, they may not be suitable for lowlatency requests if out of visibility, making ground networks essential. This highlights the complementary roles of space and terrestrial segments in quantum networking.
Satellite-based quantum networks are emerging as a promising solution for the development of a global quantum internet in the near future. The ability to leverage the advantageous lower attenuation of optical signals from satellites to ground presents an exciting opportunity to establish a robust and secure quantum communication infrastructure on a global scale. By utilizing a constellation of satellites, it becomes feasible to continuously distribute high-fidelity quantum entanglements among ground stations over long distances, overcoming the limitations of traditional terrestrial-based quantum communication systems. In this article, we first provide a brief survey of existing solutions for satellite-based entanglement distribution, highlighting the various approaches and technologies that have been employed in this rapidly evolving field. We then delve into a formulated optimal entanglement distribution problem, aiming to optimize the distribution of quantum entanglement resources across the satellite network to maximize efficiency and reliability. This problem is addressed through a detailed exploration of several different methodologies and algorithms, each tailored to specific operational settings and constraints. Our experimental results confirm the efficiency of these approaches and provide valuable insights into their practical implementation and performance. Finally, we identify several key directions for further study and development in the realm of satellite-based quantum networks.
Recent developments have reported on the feasibility of interconnecting small quantum registers in a quantum information network of a few meter-scale for distributed quantum computing purposes. Small quantum processors in a network represent a promising solution to the scalability problem of manipulating more than thousands of noise-free qubits. Here, we propose and assess a satellite-enabled distributed quantum computing system at the French national scale based on existing infrastructures in Paris and Nice. We consider a system composed of both a ground and a Space segment, allowing for the distribution of end-to-end entanglement between Alice in Paris and Bob in Nice, each owning a few-qubit processor composed of trapped ions. In the context of quantum computing, this entanglement resource can be used for the teleportation of a qubit state or for gate teleportation. After having developed a model, we numerically assess the entanglement distribution rate and fidelity generated by this space-based quantum information network and discuss concrete use cases and service performance levels in the framework of distributed quantum computing. We obtain 90 end-to-end entangled photon pairs distributed over a satellite pass of 331 s that can perform a teleportation-based controlled-Z operation with a fidelity of at most 82%.
A large scale quantum network requires the distribution of high-fidelity end-to-end entanglement. To overcome the range limitations inherent to terrestrial fiber, a leading architecture has emerged: satellite-based sources transmitting entanglement to quantum repeaters on the ground. By bridging the gap between abstract analytical frameworks and computationally heavy numerical simulations, this paper provides the first quantitative answer to the question of such a network's achievable performance with current and near-term space technology, while accounting for entanglement swapping and purification. This is achieved by integrating a detailed physical model of a satellite-to-ground link into an analytical entanglement resource estimation framework for quantum repeaters, enabling an optimization of the end-to-end entanglement rate. Our analysis, performed across leading quantum hardware platforms, shows that Low Earth Orbit satellite constellations combined with quantum repeaters employing Neutral Atom or Nitrogen and Silicon Vacancy qubits, could enable a global quantum network, distributing entanglement over distances up to 20,000 km, sufficient for connecting any two points on Earth. This work highlights the major bottlenecks in space and quantum hardware technologies, which need to be addressed, thereby guiding informed investments necessary for enabling a large scale quantum network.
Satellites and aerial platforms can be significant in the development of new telecommunications networks, allowing to deploy networks with extremely high performance even in remote areas. Recently, considering the development of quantum communication technologies, many studies are concentrated on Free Space Optic (FSO) Non-Terrestrial links, also considering that the studies performed so far on Optical Fibers (OFs) have not pointed out significant results, especially in terms of coverage. Moreover, the decrease of launch costs and the use of new satellite technologies such as CubeSats make the deployment of satellite constellations affordable. Thanks to the deployment of Non-Terrestrial Quantum Networks (NTQNs), the novel services offered by the Quantum Internet (QI) could be made easily accessible to all. In particular, Quantum Computers (QCs) can perform beyond the capabilities of any classical processor, and the interconnection of these devices on a global scale makes it possible to achieve extremely high computational capabilities, thus opening the way to new applications, such as Quantum Cloud (QCloud). Therefore, the recent studies in this area motivate this survey, which in addition to providing some base concept of quantum information, describes the current technologies needed to create quantum NT backbones. Specifically, this survey examines some studies over the period 2010–2023, which are related to the realization of quantum communications using satellites and other aerial platforms such as High Altitude Platforms (HAPS) and quantum drones. Some of the architectures that are described in this survey make use of the Software-Defined Networking (SDN) paradigm, which can be envisaged as a key enabler for the management of heterogeneous QNs in general. Furthermore, through the description of various experiments, the paper shows the applications that can be enabled by the future quantum NT backbones. In particular, in addition to improving the security of current systems through the Quantum Key Distribution (QKD), it could be possible to interconnect clusters of QCs over long distances and create extremely reliable positioning systems. Finally, the paper outlines some possible future developments.