Scientists Coax Loner Particle Out of Its Shell

Particles come in two mostly mutually exclusive varieties: loners and lovers.

Loners (fermions) keep each other at arm’s length; both you and the wall are made of fermions, which explains why you can’t walk through.

Lovers (bosons) are so gregarious that infinite numbers can pile into any space, so your body easily pushes aside the bosons in a light beam.

This week, Colorado physicist Deborah Jin and postdoctoral researcher Cindy Regal announced that they had found a new way to turn loners into lovers.

Why should physicists care?

Particles that glom together have a host of unusual properties -- for example, the ability to conduct electricity friction-free. Materials become superconductors when electrons (fermions) form pairs that move in lock step (like bosons), giving currents a free ride.

Physicists took pairing to new extremes in 1995, by enticing atoms (made of fermions) to meld into one, just as bosons do.

Jin’s group has created a novel state of matter -- a “fermionic condensate” -- that sits somewhere between the two types.

“There aren’t words to characterize this well,” said the American Physical Society’s David Harris. “This field is pretty confused at the moment.”

Still, the finding is considered important because it should lead to the development of room-temperature superconductors.

As it is, most usable materials have to be super cold to become super close; the jittery energy of heat makes bonding impossible.

Friendliness that requires such extreme frigidity is expensive. Jin’s group had to cool atoms to minus 460 degrees -- where all motion stops.