A Superatomic Sorbet
IT LOOKS ALMOST LIKE A pit inside a tiny, translucent cherry. In fact, it is a totally new state of matter--something so cold that it could never exist in nature. It popped into existence last month at the Joint Institute for Laboratory Astrophysics (JILA) in Boulder, Colo.
The cherry pit is a cluster of rubidium atoms that merged into a single huge superatom 20 microns across, or a quarter the size of a human hair. It happened when some 2,000 rubidium atoms were subjected to the coldest temperature ever: just billionths of a degree above absolute zero, or -273.15C.
Surrounded by a cloud of still normal matter, the coldest atoms collapsed into the new state, called Bose-Einstein condensate because its existence was predicted by Albert Einstein and Indian physicist Satyendr Nath Bose. This breakthrough is expected to lead to new insights in quantum mechanics, which could prove valuable in semiconductors and superconductivity.