When the Duke scientists say "ultra-cool" they mean uber-cooled to around 150 micro-Kelvin — that's only a few billionths of a degree Kelvin above absolute zero.

You use it when you need to get the absolute fastest possible processing time (and hence throughput) from your application and still maintain some degree of transactional atomicity in your processing.

Absolute zero is unattainable, but temperatures within one millionth of a degree have been reached.