The Quantum Internet is key for distributed quantum computing, by interconnecting multiple quantum processors into a virtual quantum computation system. This allows for scaling the number of qubits by overcoming the inherent limitations of noisy intermediate-scale quantum devices. Thus, the Quantum Internet is the foundation for large-scale, fault-tolerant quantum computation. Among the distributed architectures, quantum data centres emerge as the most viable in the medium term, since they integrate multiple quantum processors within a localized network infrastructure, by allowing modular design of quantum networking. We analyse the physical and topological constraints of quantum data centres, by emphasizing the role of entanglement orchestrators in dynamically reconfiguring network topologies through local operations. We examine the major hardware challenge of quantum transduction, essential for interfacing heterogeneous quantum systems. Furthermore, we explore how interconnecting multiple Quantum Data Centres could enable large-scale quantum networks. We discuss the topological constraints of such a scaling and identify open challenges, including entanglement routing and synchronization. The analysis positions quantum data centres as both a practical implementation platform and strategic framework for the future quantum internet. This article is part of the discussion meeting issue 'Bits, neurons and qubits for sustainable AI'.
The Quantum Internet is key for distributed quantum computing, by interconnecting multiple quantum processors into a virtual quantum computation system. This allows for scaling the number of qubits by overcoming the inherent limitations of noisy intermediate-scale quantum devices. Thus, the Quantum Internet is the foundation for large-scale, fault-tolerant quantum computation. Among the distributed architectures, quantum data centres emerge as the most viable in the medium term, since they integrate multiple quantum processors within a localized network infrastructure, by allowing modular design of quantum networking. We analyse the physical and topological constraints of quantum data centres, by emphasizing the role of entanglement orchestrators in dynamically reconfiguring network topologies through local operations. We examine the major hardware challenge of quantum transduction, essential for interfacing heterogeneous quantum systems. Furthermore, we explore how interconnecting multiple Quantum Data Centres could enable large-scale quantum networks. We discuss the topological constraints of such a scaling and identify open challenges, including entanglement routing and synchronization. The analysis positions quantum data centres as both a practical implementation platform and strategic framework for the future quantum internet. This article is part of the discussion meeting issue 'Bits, neurons and qubits for sustainable AI'.
This paper presents the design of scalable quantum networks that utilize optical switches to interconnect multiple quantum processors, facilitating large-scale quantum computing. By leveraging these novel architectures, we aim to address the limitations of current quantum processors and explore the potential of quantum data centers. We provide an in-depth analysis of these architectures through the development of simulation tools and performance metrics, offering a detailed comparison of their advantages and trade-offs. We hope this work serves as a foundation for the development of efficient and resilient quantum networks, designed to meet the evolving demands of future quantum computing applications.
Quantum networks play a pivotal role in quantum information science, which not only provide a secure communication platform for remote access to quantum computers but also serve as the strategic core for achieving large-scale quantum information processing, forming the foundational infrastructure for the future global-scale quantum internet. Quantum teleportation, which enables the transmission of unknown quantum states over long distances by employing quantum entanglement together with classical communication, is essential for the distribution of quantum resources in the construction of the global-scale quantum internet. To realize a global-scale quantum internet, quantum repeater protocols represent one of the most promising approaches for enabling quantum communication between any nodes. This concise review presents representative experimental demonstrations of quantum teleportation for constructing quantum networks across different physical platforms. Along this trajectory, the review discusses current challenges, open issues, and future perspectives toward scalable and practical quantum internet.
Quantum entanglement generation and distribution is key to the vision for a Quantum Internet. Existing research has focused on entanglement routing schemes and QR performance in a general network setting with strong physical layer assumptions. In reality, the required quantum memory and quantum repeater devices along with the control protocols for general quantum networks remain grand challenges in the foreseeable future. Main performance concerns at the networking layer include entanglement distribution rate and fidelity. We thereafter propose to focus more research efforts on the quantum data center network due to its structured topology and potential to support emerging distributed quantum computing applications. This paper presents a quantum data center (QDC) network architecture with novel switch architecture and protocols that feature locally buffered entanglement qubits and centralized on-demand entanglement generation and distribution. Queueing models for the switches and large-scale network simulation with the NetSquid quantum simulator demonstrate the high network throughput, scalability, and fidelity performance for the proposed QDC network architecture and protocol.
The Quantum Internet represents a paradigm shift in communication technology, leveraging quantum mechanical principles such as superposition, entanglement, and the no-cloning theorem to enable ultra-secure, high-fidelity, and potentially revolutionary global connectivity. Unlike the classical internet, which transmits bits through electromagnetic signals, the Quantum Internet transmits qubits, allowing the creation of unbreakable cryptographic channels, distributed quantum computation, and quantum-enhanced sensing networks. This paper presents a comprehensive review of the Quantum Internet, covering its underlying principles, layered architecture, enabling hardware technologies, and core communication protocols. We analyze current and emerging applications, from secure government and financial communications to healthcare and fundamental physics experiments. The study highlights the unique advantages of quantum networking, such as intrinsic security against eavesdropping, global-scale entanglement distribution, and integration with distributed computing infrastructures. At the same time, it addresses practical limitations, including distance constraints, quantum memory coherence times, infrastructure costs, and security risks associated with hardware vulnerabilities. Special attention is given to the feasibility of large-scale deployment in India, leveraging national programs such as NM-QTA and QuEST, as well as satellite-based quantum communication initiatives by ISRO. The paper concludes with a roadmap for the realization of a global quantum network, identifying technical, infrastructural, and policy challenges that must be addressed in the coming decades.
We propose an architecture for future quantum data centers with the scheduling of quantum computing flows, which integrates quantum processors, quantum switches, and quantum networks. The versatility of these data centers is discussed, highlighting their role in distributed quantum computing and quantum multi-party protocols, which include quantum cryptography and multi-party computation. We address a key challenge within this proposed architecture, namely entanglement flow scheduling which resembles its counterpart in classical data centers. Classical flow scheduling algorithms are examined and benchmarked against our proposed metrics which evaluate fairness and efficiency. We believe the proposed architecture can help to develop quantum data centers that can address the limitation of near-future Noisy Intermediate-Scale Quantum (NISQ) devices. We expect our work can inspire more research on the design of future quantum data centers.
Quantum Data Networking can significantly transform the landscape of quantum computing by enabling several small quantum computers (QCs) to form a distributed system to achieve the same computing power as a large quantum computer which is infeasible to build. However, this requires quantum state information, in the form of qubits, to be exchanged among multiple geographically distributed QCs, and there are many challenges associated with reliably transferring qubits from one QC to another efficiently. In this paper, we discuss various QDN design options, present main challenges and describe promising solutions to tackle the challenges.