“One of the enabling technologies behind a quantum internet will be quantum routers capable of transmitting quantum information from one location to another without destroying it.
That’s no easy task. Quantum bits or qubits are famously fragile—a single measurement destroys them. So it’s not all obvious how macroscopic objects such as routers in a fibre optics network can handle qubits without demolishing them.
However, physicists have a trick up their sleeve to help send qubits safely. This trick is teleportation, a standard tool in any decent quantum optics lab.
It relies on the strange phenomenon of entanglement in which two quantum objects share the same existence. That link ensures that no matter how far apart they are, a measurement on one particle instantly influences the other.
It is this ‘influence’ that allows physicists to transmit quantum information from one point in space to another without it passing through the space in between.
Of course, teleportation is tricky, but physicists are getting better at it. They’ve teleported quantum information from one photon to another, from ions to photons and even from a macroscopic ensemble of atoms to a photon.
Today, Xiao-Hui Bao at the University of Science and Technology of China in Hefei and a few buddies say they’ve added a new and important technique to this box of tricks.