“The quantum internet is not just the next-generation communication network, it is a revolution. By using the weird and counter-intuitive laws of quantum mechanics, it enables a form of information sharing fundamentally impossible in today’s internet.” These are the words of Angela Sara Cacciapuoti, Associate Professor at the University of Naples Federico II (Italy) and known for her research on quantum internet design.
As the co-founder of the Quantum Internet Research Group at the University of Naples Federico II, what are some of the most exciting research directions you’re currently exploring?
With QNattyNet, we are envisioning new ways to design and operate the quantum internet for effectively leveraging the unique power of quantum entanglement as the key communication resource, that can be distributed, coordinated, and used reliably across different systems. The ultimate goal is a unified “quantum suite” that can make quantum networks scalable. If successful, this could completely change the way we think about communication and information sharing in the future.
For those unfamiliar with the concept, how would you explain what the quantum internet is? In what fundamental way its infrastructure differs from the classical internet we use today?
Angela Sara Cacciapuoti: The quantum internet is not just the next-generation communication network, it is a revolution that uses the weird and counter-intuitive laws of quantum mechanics to share information in ways never possible before. Its building blocks are the quantum bits (qubits) instead of classical bits: while bits are either 0 or 1, qubits can be in a superposition of both.
Even more intriguingly, qubits can be entangled, meaning they share a special kind of correlation impossible in today’s internet and that defies classical logic. This is what unlocks revolutionary applications, ranging from fundamentally secure communications to linking quantum computers together into a kind of huge quantum super-computer.
But since qubits behave very differently from classical bits – they cannot be freely copied or measured without changing their states – the quantum internet requires a completely new design compared to the classical internet, one built around quantum repeaters, quantum memories, and photon channels, to allow long-distance quantum communications. Through these components, communication protocols like quantum teleportation and entanglement swapping can be exploited. Despite relying also on optical fiber, the quantum internet is not just an upgrade of the classical one, but a radically new way of connecting and sharing information.
How is the quantum internet expected to be used in practice? Do you envision it being widely accessible, or will it primarily serve specific sectors or users?
Angela Sara Cacciapuoti: Initially, the quantum internet will serve specialised sectors that require high levels of security and computational power, such as government agencies, financial institutions, research communities and critical infrastructures.
One of its first applications will be ultra-secure communication, initially through quantum key distribution – a form of encryption based on the quantum properties of particles – and, in the future, through quantum teleportation, where thanks to quantum entanglement the message does not even travel through the channel, by making eavesdropping impossible.
Another powerful use will be distributed quantum computing, where quantum processors, connected through the quantum internet, can work together as a virtual machine, with their combined power growing exponentially as more are added. Over time, as the technology matures, the quantum internet will likely become more widely accessible.
The classical internet has been a powerful tool to expand access to knowledge, but it has also enabled surveillance, disinformation and other anti-democratic uses. Looking ahead, do you see potential risks or unintended consequences associated to the quantum internet?
Angela Sara Cacciapuoti: Every major leap in technology brings both opportunities and risks, and the quantum internet will be no exception. While it promises unprecedented security, it could also raise new challenges if access is limited to a few players, creating monopolies or widening the digital divide.
There is also the possibility of a misuse of quantum technologies, for instance by exploiting unbreakable encryption in ways that hinder governance or transparency, much like what we see today with AI.
Anticipating these risks by developing ethical and regulatory frameworks, in parallel with technical progress, is essential to ensure the quantum internet empowers societies as a whole. In this direction, it will be essential to facilitate access to knowledge through open-source policies, as Europe is already promoting.
What are the key scientific and technological hurdles that must be overcome before a fully operational European quantum internet becomes a reality?
Angela Sara Cacciapuoti: We must boost the performance and scalability of quantum hardware components – especially repeaters and memories – which are essential for extending entanglement over long distances. Another big challenge is represented by quantum transduction, namely making different types of quantum platforms work together seamlessly and reliably.
We need to design radically new protocols, tailored for the unique features of quantum entanglement. Developing scalable open-source network simulators to test these protocols is also essential before real-world deployment, which is actually very expensive. Overcoming these hurdles will require not only scientific breakthroughs, but also coordinated engineering efforts across Europe.
There is growing global competition to build robust quantum internet infrastructure. How is Europe currently positioned in this race, and where do you see the greatest opportunities – or gaps – for improvement?
Angela Sara Cacciapuoti: Europe holds a strong position in this race, thanks to sustained investment in fundamental research through initiatives like the European Research Council (ERC). Blue-sky projects, like my ERC QNattyNet, drive long-term breakthroughs by exploring radically new architectures and ideas.
While other regions often emphasise short-term prototyping, Europe’s strength lies in its commitment to deep science. But to remain competitive, we must better connect these foundational efforts to scalable technologies, by encouraging tech transfer, investing in training the next generation of quantum experts, and ensuring coordinated infrastructure deployment across countries.