https://phys.org/news/2018-06-scientists-demand-entanglement-link.html

Scientists at QuTech in Delft have are now the first to experimentally generate entanglement over a distance of two metres in a fraction of a second, on demand, and theoretically maintain this entanglement long enough to enable entanglement to a third node. "The challenge is now to be the first to create a network of multiple entangled nodes—the first version of a quantum internet," professor Hanson says.

In 2015, Ronald Hanson's research group was the first to generate long-lived quantum entanglement over a long distance (1.3 kilometres), , allowing them to provide full experimental proof of quantum entanglement for the first time. This experiment is the basis of their current approach to developing a quantum internet. Distant single electrons on diamond chips are entangled using photons as mediators. However, this experiment has not had the necessary performance to create a real quantum network. Hanson says, "In 2015, we managed to establish a connection once an hour, while the connection only remained active for a fraction of a second. It was impossible to add a third node, let alone multiple nodes, to the network."