Get ready: the quantum internet is a next-generation disruptive technology that is now closer to fact than fiction. Researchers predict that practical quantum communications may be here within 10 to 15 years.
There is an expectation that quantum-based networks/networking (Quanets) will become a reality in the near future. Just as the classical Internet fostered a high-speed hyperconnected ecosystem that enhanced innumerable aspects of human life and global scientific research, a quantum-based ecosystem will greatly enhance the capabilities to address and solve complex problems of all types and will provide an enhanced panoply of tools for researchers in practically every scientific field. Network connectivity refers to the ability to go beyond point-to-point communication and support exchange data among multiple end nodes. Thus, basic desiderata for Quanets entail the support of adequate functionality, multi-endpoint connectivity, and the ability of bridging meaningful geographic distances. Quanets are seen as a disruptive technology, although this technology is still in its infancy. Currently Quanets are perceived as being complementary to classical networks and are not intended to replace them.
While quantum computing faces many implementation challenges, practical quantum communication technologies exist today. This means quantum networking services such as quantum key distribution (QKD) can already be utilized. Adoption of quantum technologies into existing infrastructure will likely evolve into fully-fledged quantum networks that grow in tandem with advances in quantum computing. This article describes the unique challenges, evolving stakeholders, and possible architectural components of the coming quantum internet.
Following the emergence of quantum computing, the subsequent quantum revolution will be that of interconnecting individual quantum computers at global level. In the same way that classical computers only realised their full potential with the emergence of the internet, a fully realised quantum internet is the next stage of evolution for quantum computation. This work examines in detail how the quantum internet would evolve in practice, focusing not only on the technology itself but also on the implications it will have economically and politically. We present both original ideas, as well as an extensive review of relevant and related background material. This work begins with a description of classical networks before introducing the key concepts behind quantum networks, such as quantum internet protocols, quantum cryptography, and cloud quantum computing. The work is divided into technical sections (requiring only a basic knowledge of the notation of quantum mechanics), for those interested in mathematical details, as well as non-technical sections for those seeking a more general understanding. We target this work very broadly at quantum and classical computer scientists, classical computer systems, software and network engineers, physicists, economists, artists, musicians, and those just generally curious about the future of quantum technologies and what they might bring to humanity.
Entanglement distribution is a fundamental building block of quantum communication networks, enabling the secure and reliable exchange of quantum information over long distances. Unlike classical communication, quantum networks exploit the unique properties of quantum entanglement to support applications such as quantum key distribution, quantum teleportation, distributed quantum computing, and networked quantum sensing. Although significant progress has been made in recent years, the efficient generation, transmission, and preservation of entangled states remain major research challenges due to photon loss, decoherence, and limitations in current communication infrastructure.This review provides a comprehensive overview of entanglement distribution in quantum communication networks, focusing on the technologies that enable practical implementation and the latest experimental developments. It discusses key approaches for generating and distributing entangled photons through optical fibers, free-space links, and satellite-based communication, together with supporting technologies such as quantum repeaters, quantum memories, and photonic devices. The review also examines recent experimental demonstrations that have advanced long-distance quantum communication while highlighting the technical barriers that must be overcome for large-scale deployment. Finally, emerging applications and future research directions are presented, including the development of scalable quantum networks, the quantum internet, and secure global communication systems. This review aims to provide researchers and students with a clear understanding of the current state of entanglement distribution and its growing role in next-generation quantum communication technologies.