A thousand violinists play a single note. Each hears only their neighbor, yet the hall gives birth to one unified sound. So it is in the quantum world: clouds of thousands of atoms can be linked by an invisible thread, entanglement. This means that if you touch one atom, another responds instantly, even if it is far away.

Previously, such a link was established only between single atoms, as if an orchestra played one violin at a time. Now scientists have shown that you can link entire huge clouds at once, up to a million atoms in each. To do this, neighboring clouds interact, and then the intermediate ones are measured in a special way. It is like a conductor who waves a baton, and the whole orchestra plays in sync, even though the musicians cannot see him.

Previously it was unclear whether such a link would hold up with a million atoms and noise. Now it is clear: it holds up. This matters for those building a quantum internet, a network where information is transmitted using entanglement. But exactly how to apply such a powerful link is not yet clear. The music is playing, but the notes have not yet been written.