• Experimental physicists at MIT have successfully cooled molecules in a gas of sodium potassium (NaK) to a temperature of 500 nanokelvins—just a hair above absolute zero and over a million times colder than interstellar space. The researchers found that the ultracold molecules were relatively long-lived and stable, resisting reactive collisions with other molecules.
  • The molecules also exhibited very strong dipole moments—strong imbalances in electric charge within molecules that mediate magnet-like forces between molecules over large distances. By first cooling atoms to ultralow temperatures and only then forming molecules, the group succeeded in creating an ultracold gas of molecules, measuring one thousand times colder than what can be achieved by direct cooling techniques.
  • To begin to see exotic states of matter, Zwierlein says molecules will have to be cooled still a bit further, to all but freeze them in place. "Now we're at 500 nanokelvins, which is already fantastic, we love it. A factor of 10 colder or so, and the music starts playing."

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