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Physicists Observe the Majorana Fermion, Which Is Its Own Antiparticle
Charliemopps writes: "For the first time Princeton University scientists have observed a Majorana fermion, a long-predicted but never observed exotic particle that acts as both matter and anti-matter (abstract). "The setup they created starts with an ultrapure crystal of lead, whose atoms naturally line up in alternating rows that leave atomically thin ridges on the crystal's surface. The researchers then deposited pure iron into one of these ridges to create a wire that is just one atom wide and about three atoms thick. ...[Next, they] placed the lead and the embedded iron wire under the scanning-tunneling microscope and cooled the system to -272 degrees Celsius, just a degree above absolute zero. After about two years of painstaking work, they confirmed that superconductivity in the iron wire matched the conditions required for Majorana fermion to be created in their material." The particle is surprisingly stable. Being in both states at once seems to make it interact very weakly with its surrounding material. This could also be a major step towards quantum computing.
Why is that just thrown in there? It seems kind of random.
"Pizza Hut has created a bacon, cheese, AND sausage stuffed crust pizza! This amazing pizza is very delicious. This could also be a major step towards quantum computing."
The summary (and the article!) imply that it is rare and strange for a particle to be its own antiparticle. This is not the case. Plenty of boson and mesons are their own antiparticles: photons, gluons, pions, etc. This isn't a particularly weird situation.
However, fermions are another story. Fermions and bosons are the two kinds of fundamental particles. They behave very differently. While there are bosons that are their own antiparticle, there are no known fermions that have this property. All the fermions we know of are Dirac-type. It's been long postulated that there could be Majorana-type fermions, which, among other things, are their own antiparticles.
It's interesting, but not quite as crazy as implied.
A Majorana particle is it's own antiparticle; such as, for example, a photon.
Most fermions have different antiparticles from themselves: Protons are notably different from anti-protons, electrons are different from positrons, and so on. The one exception is the neutrino, for which the question is not yet settled.
If the neutrino is its own antiparticle, we should see double-beta-decay events. A beta decay emits a neutrino, so if two happen simultaneously the neutrinos should annihilate if they are their own antiparticle. (Wikipedia link)
As yet no experiment has seen double-beta-decay, so it's likely that the neutrino has a distinct anti-neutrino - an intriguing prospect.
The article referenced in the post does not identify the fermion involved, so one can only assume that it's a "quasi particle", which is a type of vibration. Essentially a phonon (sound wave) with fermion-like properties.