quantum computing

Device-independent quantum key distribution (DI-QKD) is a key step toward the quantum internet, as it provides the highest level of cryptographic security allowed by quantum mechanics. For it to have practical applications in a communication network, it must be achieved between nodes that are sufficiently far apart. An article published in Science demonstrates DI-QKD for the first time between two single-atom nodes connected by 100-kilometer-long fibers. This distance would be sufficient to achieve cryptographic security at a metropolitan scale.

The Royal Swedish Academy of Sciences has awarded the 2025 Nobel Prize in Physics to John Clarke, Michel H. Devoret, and John M. Martinis, who demonstrated both the quantum tunnelling effect and quantised energy levels in a system small enough to fit in the palm of your hand. These advances have served to develop the next generation of quantum technology, including quantum cryptography, quantum computers and quantum sensors.

An international team has successfully sent quantum messages 254 kilometres away using an existing telecommunications network in Germany. A quantum Internet would theoretically be faster and more secure, and this demonstration suggests that this type of communication can be achieved in real-world conditions. The results are published in the journal Nature.

UNESCO has proclaimed 2025 as the International Year of Quantum Science and Technology. This initiative aims to ‘raise public awareness of the importance of quantum science and its applications’, as well as to celebrate and recognise 100 years since the initial development of quantum mechanics. But why is this scientific discipline so relevant? We explore with experts the key issues and the impact of quantum science and technology on the development of our society.

A team in the US has for the first time achieved quantum teleportation over 30 kilometres of fibre-optic cable already carrying internet data traffic, says a study published in the journal Optica. This type of teleportation would allow quantum communication to be combined with existing internet cable infrastructure. 

A team of physicists led by Harvard University (USA) has succeeded in linking two quantum memory nodes 35 kilometres apart using existing fibre optics in the Boston area (USA). This is the longest distance achieved to date. According to the authors, who publish their results in the journal Nature, ‘demonstrating that quantum network nodes can intertwine in the real-world environment of a busy urban area is an important step towards practical networking between quantum computers’. 

A team of researchers, led by IBM's Thomas J. Watson Center, has shown that a quantum computer can already help in the calculation of practical scientific problems that are inaccessible to today's classical computers. The "noise" and errors that accumulate still limit the applications of such computers, but the new study shows that, after adding a protocol that reduces these problems, a 127-cubit quantum computer is capable of simulating extremely complex physical states with high reliability. The results are published in the journal Nature.

The journal Nature publishes a quantum simulation of a holographic wormhole on a quantum processor. The demonstration, carried out with the Google Sycamore processor, represents a further step towards the possibility of studying quantum gravity in the laboratory.

The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Physics to Alain Aspect, John F. Clauser and Anton Zeilinger for their experiments with entangled photons, establishing the violation of Bell's inequalities and becoming pioneers in quantum information science.

A 'quantum internet' would allow, among other things, the flow of inviolable secret messages. Building such a network involves teleporting information between non-interacting elements of the system, something researchers in the Netherlands claim to have achieved. They publish it in Nature.