The Clarendon Copy-Paste Paradox

Why teleportation isn't the same as cloning

Mission 6: Quantum Teleportation. Part of the Quantum Courier Service, a free course from the Oxford University Quantum Information Society.

Listen closely, old sport: we've a rather sensitive VIP qubit currently sitting in the Oxford vault, and it needs to reach the Clarendon Lab post-haste before the Echo Network initiates a breach. Tempting as it is to reach for the "Hollywood" copy-paste button, the No-Cloning Theorem isn't a mere suggestion; it's the law of the universe, and any attempt to photocopy a quantum state will simply shatter it into digital ruin. So we do it the proper way: quantum teleportation. Pick an Input state to load into Alice, then press teleport. Watch closely what that costs us: measuring Alice's qubit effectively vaporises the original on the spot, and Bob is left holding nothing usable until two ordinary classical bits crawl across the gap at light speed. Try to read Bob mid-transit and you get a pure coin flip; only once those two bits land does his qubit snap into the exact state we started with. Nothing outran light, and yet the state made the journey intact. Chop chop!