Physicists coax molecules into exotic quantum state — ending decades-long quest

A decades-long quest to create a Bose–Einstein condensate from molecules is finally over. Physicists cooled sodium-caesium molecules until they were almost stationary — which, thanks to Heisenberg’s uncertainty principle, meant their positions were so uncertain that they became indistinguishable and formed a single gigantic quantum state. Physicists have forced atoms into this bizarre state of matter since 1995, but molecules are much harder to cool. The key was using microwave fields to keep heat-generating collisions between molecules under control.