How Cold Atoms Might Help Physicists Understand Superconductors

One of the big science stories at the end of last week was an announcement from MIT that researchers there have used a small quantum computer to factor the number 15. That might not seem like much of an achievement– my seven-year-old daughter can probably do it– but it’s a demonstration of “Shor’s algorithm,” which is one of the killer apps for quantum computing. Factoring very large numbers is a hard problem for a normal computer, and as a result some mathematical cryptography systems encrypt messages in a way that requires you to know the factors of a big number to decrypt them. But Peter Shor of IBM showed in 1994 that there’s a way to factor numbers more efficiently using a quantum computer. This made the previously abstract subject highly relevant to the interests of people like the National Security Agency, and money started flooding into the field.