The team managed to get their SrF molecules chilled to around 300 microkelvin in one direction. (scientificamerican.com)
In the late 1980s laser specialists refined the technique to cool atoms down to several microkelvin. (newscientist.com)
In breaking this record, Eric Cornell and his colleagues in Boulder cooled rubidium atoms to 5 microkelvin by optical molasses, and then turned off the lasers while keeping the atoms trapped in a magnetic field. (newscientist.com)