The technique they use is similar in principle to how atoms are doppler cooled for BEC experiments (much of that early research was also at JILA), but it looks

The technique they use is similar in principle to how atoms are doppler cooled for BEC experiments (much of that early research was also at JILA), but it looks like the window has been narrowed significantly. What's special about this is that it's a step towards experiments involving gravity at non-macroscopic distances. If quantum gravity is possible, it would be quite exciting for the graviton to be discovered experimentally before theorists figure it out.