Dutch researchers have achieved the first teleportation of quantum information between network nodes not directly connected to each other. An essential step for the development of an ultra-secure Internet.
A first
Strange quantum phenomenon involving two particles or distant objects sharing the same properties, theentanglement is at the center of proposals to ensure the privacy of online communications. If one of the main approaches currently being explored relies on a network of quantum bits connected (or qubits), entangled with qubits located elsewhere in the network, this had until now only been demonstrated for neighboring nodes, directly connected.
In the context of work published in the journal Nature, Ronald Hanson and his colleagues from theDelft University of Technologyto Netherlandsconstructed a simple network consisting of three qubit nodes, named Alice, Bob et Charlie. And Alice et Charlie were not directly connected (they only shared an indirect link via Bob), they were quantum entangled, meaning that it was impossible to measure information from one of them without changing the state of the other.
« When Charlie’s quantum state was changed, Alice’s also changed, and the information somehow teleported through Bob without going directly through him. “, Explain Hanson. « It is a type of teleportation comparable to those that can be seen in science fiction films. State, or information, vanishes on one side only to reappear on the other, and since it doesn’t physically traverse the space in between, data can’t get lost either.. »
Although this form of entanglement has been theoretically possible for decades, this is its first real demonstration, relying largely on the use of specific crystals, allowing the qubits to be stored for an extended period.
Securing communications
Contrary to what one might think, the deployment of a quantum internet network would not result in increased throughput: even if the state of two remote nodes in the network changes instantaneously, users sharing information/data would do so through traditional, non-quantum devices.
« There are many potential applications, this would enable the secure sharing of information, for example by preventing servers from tracing the source of the data they process “, Explain Hanson.
While his team was the first to design and test a quantum network in which non-neighboring nodes are entangled, previous work had explored other types of quantum communication, notably involving entangled photons.
« Testing different approaches is essential “, highlighted Charles Adamsof the’durham universityau UK. « We do not yet know which one will succeed. It may be a hybrid technology. »