A long-sought new form of matter has been created for the first time. The matter, called a fermionic condensate, consists of atoms that are ordinarily forbidden to exist in the same quantum state but have been tricked into it by linking into pairs.
It occupies the middle ground between loosely linked particles that form superconductors and tightly bound ones in Bose-Einstein condensates, another exotic form of matter produced fleetingly since 1995. The creation of the new condensate is considered the crucial first step toward producing superconductors that work at room temperatures.
"This is a tremendous success," says Keith Burnett, a physicist at Oxford University, UK. The University of Colorado researchers who accomplished the feat are "fantastic experimentalists", he says, adding that scientists around the world have been racing to overcome the technical challenges of creating the matter.
Much of the difficulty centres on the nature of fermions. These are subatomic particles such as protons, neutrons, and electrons that have half-integer spins (1/2, 3/2, etc) and atoms comprised of odd numbers of the particles.
Unlike bosons, another form of elementary particle that have integer spins (1, 2, 3, etc), identical fermions are prevented by the laws of quantum physics from sharing the same state of being. For example, identical fermions cannot share the same location or momentum. But photons, which are bosons, can - which is why lasers work.
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