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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.
It's sure a particle alright.
Not it is not. It is really just a simulation of a particle. All they have done is create a system which behaves like we think a majorana fermion should behave. They have emphatically NOT created a new fundamental particle. What they have done is hype up the interesting physics they have done to make it look like they are doing particle physics which they are not.
Don't get me wrong: this is definitely an interesting result but it is unnecessary, and rather deceptive, to present it as particle physics when it isn't. Such experiments are very interesting and worthwhile because they may improve our understanding of how a majorana particle behaves. However if we found an inexplicable deviation between the way that this "simulated particle" behaves and how a theoretical majorana fermion is expected to behave after 'debugging' we would put it down to them not simulating the particle correctly and we would not be rewriting the fundamental laws of physics.
Ok, so if you know this stuff, what does it mean for a particle to be its own antiparticle? Does that mean if it comes into contact with another such particle, they're both annihilated? Does that mean that they're neutral to matter and anti-matter, or do they still somehow fall into one of those categories?