Researchers in Austria have solved a problem plaguing long distance quantum teleportation: verifying that information has been transmitted has required the quantum link itself to be destroyed, preventing any further use.

The solution was to reduce the intensity of the source used to fire photons at the entangled pair, lowering the total number of photons in the system and hence also the number of false positives. Now, if the two interacting photons are detected, it is more than 97 per cent certain that the state has been teleported.

This is above the accuracy theoretically needed to extend the use of quantum communication by the use of “quantum repeaters” that teleport qubits over long distances.