Boffins want to put Quanta in containers, after docking
Hyperscale hepcats, back off - this one's about testing entanglement afloat
Don't laugh: a group of Japanese and Australian boffins want to use container ships to carry around entangled quanta.
Entanglement is hard to maintain over any great distance – a few tens of kilometres through optical fibre, a hundred or so through the atmosphere – because of noise. Repeaters are forbidden by the “no-cloning theorem”*.
Quantum memories are a different matter. They're developing quickly in the labs, to the point where they can retain quantum states for a decent length of time, and that opens up an RFC 1149-like solution to the question of communicating quantum states.
No, you can't quite stick the quantum memory on a pigeon's leg. You can't even follow the old dictum of “never underestimate the bandwidth of a van-full of disks”, because quanta need to be kept cold to retain their state.
A shipping container is a different thing: room enough for a tiny chunk of quantum memory plus the, umm, container-load of refrigeration needed to retain the state. And that's just what the authors of this presumably-whimsical Arxiv paper propose.
“We assume that 1m3 is occupied by quantum memories and the remaining 39m3 is reserved for power, refrigeration, and control infrastructure. Each of these units is the quantum equivalent of a memory stick”, the paper states.
Since you have to deal with noise in quantum systems, there's a six-to-one redundancy assumed in the “containerised quanta” proposal: “our protocol requires an additional six containers for every one container in transport”, the paper notes.
In case you still think this is an IP-over-avian-carrier style joke, the authors say that “once quantum computers are commonplace, entanglement will be the fungible resource that enables a vast range of distributed applications”. And as you all know, the correct use of “fungible” makes any argument indisputable.
If you can stand the latency, the researchers from reckon that some realisations - like quanta in silicon - would beat the daylights out of any other protocols for quantum communication bandwidth, with a top capacity of 8.7 x 1012 Hertz. ®
*Bootnote: No-cloning means no free lunch. You can't copy entanglement, because when you observe the entanglement, you destroy it. There's a longer explanation of it at Wikipedia. ®