Teleportation trick shows promise for a future quantum internet

Alex Wilkins

An important step towards building a super-secure quantum internet is using a quantum network.

There are linked properties of objects that share a quantum entanglement. Privacy could be greatly improved with a quantum internet because ofanglement. One idea is to build a network of connected quantum bits, or qubits, which are entangled with qubits elsewhere in the network rather than with the neighbours. The network qubits have been demonstrated with directly connected qubits.

Ronald Hanson and his colleagues at the University of Technology in the Netherlands built a simple network containing a number of diamond-based qubits. Alice and Charlie shared an indirect link with Bob. It is impossible to measure information from one of them without changing the state of the other.

Alice's state also changed when Charlie's quantum state changed.

It's like in science-fiction movies, where the state disappears on one side and reappears on the other.

Read more: The quantum experiment that could prove reality doesn’t exist

It was only successfully demonstrated here because of the qubits at the nodes, which can hold quantum states for longer time periods than standard qubits.

A quantum internet network doesn't offer any increases in speed over a conventional system, even though two of the network's nodes change at the same instant. Users sharing information about changes to the network must use non-quantum communication. There are many applications that we still have to find out about, such as a data server that can never discover the source of data they are crunching.

While Hanson and his team are the first to build and test a quantum network in which non-neighbouring nodes are entangled, other teams have been experimenting with different kinds of quantum communication.

Charles Adams at Durham University, UK says that trying these types of experiments on different platforms is very important.

The journal Nature has a reference.