By Ian Evenden
Is a quantum network the next step for how we transfer data?
We like phat pipes, and we cannot lie. And over the past 20 years we’ve seen internet connections change from dial-up to ADSL over copper wire, to today’s fibre-optics. So what’s next for how we transfer data?
Imagine a network that, instead of using pulses of light to send signals, uses the properties of photons themselves. This is a quantum network, and it relies on something Einstein wasn’t very fond of: quantum entanglement. Decried as ‘spooky action at a distance’ by the moustachioed relativity-theoriser, entanglement means creating a pair of photons in such a way that, when you measure the quantum state of one, you immediately know the same property of the other no matter how far apart they are. Transferring information in this way is known as quantum teleportation, but rather than men in red shirts doomed to die, what’s teleported here is the quantum information. If you’re really clever, this is enough to build an internet.
Such really clever people include graduate student Samantha Davis and Dr Raju Valivarthi, who both work in the Division of Physics, Mathematics, and Astronomy at the California Institute of Technology. They published a paper in 2020 detailing how, using “state-of-the-art low-noise superconducting nanowire single-photon detectors” (and off-the-shelf optics) they were able to teleport qubits at a wavelength commonly used in telecommunications down optical fibres, with a fidelity of 90%. Clearly, with an error rate of 10%, they’re not quite there yet, though work on this is ongoing both at Caltech and Fermilab.
What’s perhaps most interesting about the Caltech work is the way it uses common networking components, and can interface with today’s internet.Continue reading… “How teleportation is powering the internet of the future”