An initial network for exchanging information via three-step teleportation was created by European scientists, thus taking an important step towards the development of the ultra-secure quantum Internet.
The Quantum Internet – which has been an unexpected daylight for another decade – will be a large -scale network that connects users through new applications and impossible to achieve with the classic webexplanation to AFP Ronald Hanson of the University of Delft (Netherlands), co-author of this work published in the journal Nature.
The exchange of information does not take place in the form of conventional bits – the 0s and 1s at the base of computing – but of quantum bits (qubits).
These qubits take advantage of the laws of quantum physics, which govern the world on the scale of the infinitely small. One of these properties is entanglement, also called entanglement, a strange phenomenon in which two entangled particles act identically regardless of the distance between them: as if connected by an invisible thread, they are both of the state.
The state of a tangled qubit is shared with one, and their coordination is so perfect that we speak of teleportation: in theory, any change in the characteristics of one immediately changes the other, even at the other end of the world. .
Quantum bits can currently be transmitted via optical fibers, but teleportation remains limited: beyond a hundred kilometers, the signal is impaired or even lost. If we want to maintain end-to-end entanglement, the qubits must be directly linked by a chain quantity.
This is the work described in the study by Nature, where scientists introduced a relay, to extend the range of communication. Quantum communication, limited to two actors commonly called Alice and Bob, can now rely on a third character, Charlie.
The experiment took place in two QuTech laboratories, a collaboration between Delft University of Technology and the Dutch organization for applied sciences TNO.
Diamond -based qubits are placed in a circuit consisting of three interconnects called quantum nodes. The Alice and Bob nodes are located in two laboratories a few meters away, and are connected via fiber optics, and similarly Bob is directly connected to Charlie. Alice and Charlie can’t talk right now.
The researchers first encapsulated the physically connected nodes (the Alice-Bob couple and the Bob-Charlie couple). Bob was then used as a go-between, and through a process of tangled swapping, Alice and Charlie were able to tangle.
Although not physically connected, the latter were able to send messages directly to each other. The signal also has excellent quality, without any loss – a challenge given the extreme instability of a quantum bit.
And this transmission is able to take place in the greatest secret, as required by the laws of quantum: with entanglement, any attempt to intercept or eavesdrop on the message automatically changes to qubits, destroying the message itself.
This first embryonic quantum teleportation network allows for large -scale connections: it proves on a laboratory scale the principle of a reliable quantum repeater – the famous Bob – that can be placed between two nodes 100 km away. , so the strength increases. of the signal.
The innovation described in Nature represented a breakthrough for basic science and the real-world solutions to take applied quantum physics to the next levelwelcome scientists to a comment News and Watching published along with the study in Nature.
When he talks about the quantum Internet, physicist Ronald Hanson describes a universe where communications would be “ultra-secure”, and the quantum computer accessible in the cloud with confidentiality of our data guaranteed by the natural laws of physics, a network of hypersensitive sensors ….
Finding quantum web applications is a field of research in itselfadded the researcher, hoping to see this new world born in less than 20 years.
Source: Radio-Canada
