Published online 19 October 2007 | Nature | doi:10.1038/news.2007.171

Column: Muse

Swiss elections get spooky

High-profile applications of quantum trickery raise the question of what to call these new technologies. Philip Ball doubts that one proposal will catch on.

Quantum technologies have started to creep into real life. The Swiss general elections this Sunday, for example, are set to use quantum cryptography in the voting.

The impression being given is that Swiss democracy is being safeguarded by the fuzzy shroud of quantum physics, which can in principle provide a tamper-proof way to transmit information. But the reality is that just a single state — Geneva — is using quantum cryptography (a commercial technology that has already been trialled by banks and financial institutions; see Seeking absolute security), and then only to send tallies from a vote-counting centre to the state government’s repository. The votes themselves are being delivered by paper ballot — which, given the controversies over electronic voting systems, is probably still the most secure way to collect them.

So it all seems like a bit of a publicity stunt. (In any event, with accusations of overt racism in the campaigning of the right-wing Swiss People’s Party, hacking of the voting system is perhaps the least of the worries in this election.) But it would be churlish to portray this use of quantum cryptography as worthless on that account. There is no harm in using a high-profile event to advertise the potential benefits of the technology. If nothing else, it will get people asking what quantum cryptography is.

The method doesn’t actually make transmitted data invulnerable to tampering. Instead, it makes it impossible to interfere with the transmission without leaving a detectable trace. Some quantum cryptographic schemes use the quantum-mechanical property of entanglement, whereby two or more quantum particles are woven together so that they become a single system. Then you can’t do something to one particle without affecting the others with which it is entangled — so intercepting data encoded in one of a pair of entangled particles becomes evident in the behaviour of the other.

Just the beginning

Quantum cryptography is just one branch of the emerging discipline of quantum information technology, in which phenomena peculiar to the quantum world, such as entanglement, are used to manipulate information. Other applications include quantum computing, in which the ability to maintain quantum particles in superpositions — mixtures of the classical states that would correspond to the binary 1s and 0s of ordinary computers — vastly boosts the power and capacity of computation.

Quantum teleportation — the exact replication of quantum particles at locations remote from the originals — also makes use of entanglement.

These new quantum tricks draw on ideas rooted in the early days of quantum theory, when its founders were furiously debating what the theory implied about the physical world. Albert Einstein doubted that quantum particles could really have the fuzzy properties ascribed to them by the theory. He proposed a thought experiment in which this aspect of the theory seemed to imply a ‘spooky action at a distance’, whereby quantum particles can communicate instantaneously between themselves no matter how far apart they are.

Einstein thought that this just couldn’t happen. But we now know that this action at a distance is real — it is the result of quantum entanglement. This apparent absurdity is simply the way the world is. And now people are taking advantage of it. (IBM physicist Charles Bennett — one of the pioneers of quantum information technology — will surely get a Nobel prize some time soon.)

Now we need a name

So far, most researchers have been happy to talk about ‘quantum cryptography’, ‘quantum computing’ and so forth, under the umbrella phrase of quantum information technology. But is that a good name for it? Charles Tahan, a physicist at the University of Cambridge, UK, who is working on these technologies, thinks not. In a recent preprint1, he draws inspiration from Einstein and proposes calling it all "spookytechnology".

“No scientist is going to want to tell people that he or she is working in a field that sounds as though it was invented by Caspar the Friendly Ghost”

This, says Tahan, would refer to “all functional devices, systems and materials whose utility relies in whole or in part on higher-order quantum properties of matter and energy that have no counterpart in the classical world”. By higher-order, Tahan means things such as entanglement and superposition. He argues that his definition is broad enough to contain more than quantum-information technology, but not so broad as to be meaningless. (In that respect, Tahan addresses the shortcomings of ‘nanotechnology’, a field that is not really a field at all but instead a ragbag of many areas of science and technology ranging from electronics to biomedicine.)

But Tahan’s term is unlikely ever catch on because it violates one of the most fundamental prohibitions in scientific naming: don’t be cute.

No scientist is going to want to tell people that he or she is working in a field that sounds as though it was invented by Casper the Friendly Ghost. True, ‘buckyballs’ gained some currency as a term for the fullerene carbon molecules (despite Nature 's best efforts to avoid the word after C60's original discovery) – but its use remains marginal. And thankfully ‘buckytubes’ never caught on — everyone calls them carbon nanotubes.

Don't be silly

Attempts to label fields rarely succeed, because names have a life of their own. ‘Nanotechnology’, when coined in 1974, had nothing like the meaning it has today — it referred to rather conventional micromechanical engineering. ‘Spintronics’, the field of quantum electronics that lies behind this year’s physics Nobel, is arguably a slightly ugly and brutal amalgam (of ‘electronics’ and the electron’s quantum property of ‘spin’), yet somehow it works.

Certainly, names need to be catchy: laboured plunderings of Greek and Latin are never popular. But catchiness is an imponderable concept that can’t be produced on demand.

That's why I'll refrain from trying to improve on Tahan's proposal - we should let the market decide. But I'm afraid I can't see the Geneva elections being remembered as a landmark in spookytechnology. 

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