Slashdot Mirror
First Experimental Success of a Superfluid
J writes "Researchers at Rice University have created and observed a state of quantum superfluidity. Cooled to temperatures near absolute zero, fermions overcome their natural tendency to repel one another. These half-spin particles become dominated by the Strong force and couple up in pairs that behave as one particle. Major benefits to matter in a superfluid state include superconductivity, a state where electrons would flow freely with no resistance, thus preserving the most amount of electrical charge during passage and providing the ability to save billions of dollars in 'lost electricity'. Although the conditions set for this experiment are very unlikely to be able to exist outside of a laboratory, we now know that superfluidity is a concept that can exist. Future research in this topic is assumed to be finding a material that exists in a superfluid state at room temperature."
News for nerds. Stuff about matters?
"Scientists in Antarctica discover superfluid at room temperature"
May the Strong force be with you.
The phrase "link up" is misleading. What happens is that the Fermi sea becomes unstable to the formation of statistically correlated pairs of electrons below a certain temperature. They never violate the Pauli Exclusion principle, but the spin-statistics behavior changes so that they can be thought of as Bosons.
"I'm not exactly sure how a Bose-Einstein condensate creates a single quantum state, but is this more of the same?"
Again, the Slashdot article is poorly worded, or the chao who wrote it doesn't really understand what he's talking about:
In a BEC, all the Bosons occupy one single particle quantumstate, and you thus have a highly coherent many particle state that is not averaged out over large length scales.
l'Homme n'est Rien l'Oeuvre Tout: Gustave Flaubert to George Sand
- Superfluidity isnt new, it's been around for 50+ years.
- Superfluidity is only tangentially related to superconductivity.
- Superfluidity is not particularly useful in and of itself.
- Superfluidity among ferminons *is* new and interesting to physics geeks.
As to its applications to daiily life, well, unlikely in the short run.Superfluid materials are well-known; the first example, the boson helium-4, was discovered in 1937. The superfluidity of helium-3, a fermion, was shown to be a superfluid in the 1970s.
Superfluidity occurs when particles pair up (half spin-up and half spin-down) to produce a material without viscosity, in a manner analogous to that of the electron Cooper pairs of superconductivity. The novelty here is that superfluidity has been shown to occur in particle populations in which there is an unequal number of spin-up and spin-down particles, and the discovery of a phase change in which "when unpaired spin-up atoms rose above 10 percent of the total sample, the unpaired loners were suddenly expelled, leaving a core of superfluid pairs surrounded by a shell of excess spin-up atoms" (from TFA).