(ORDO NEWS) — Researchers at Purdue University in West Lafayette, Indiana, have received new experimental confirmation of the group behavior of electrons, which produces anyions – quasiparticles that exist in two-dimensional systems. An article about this was published in Nature Physics.
Before anyons were discovered, elementary particles and quasiparticles were divided into two large groups: fermions and bosons. The first, for example, include the carriers of an electric charge – electrons, and the second – photons. Fermions and bosons have a number of fundamental differences: for example, fermions can have fractional spin, while bosons can only have integer spin; fermions have antiparticles, but bosons do not; Pauli exclusion principle applies only to fermions.
The existence of anyons was first theoretically substantiated back in 1977 by a group of Norwegian physicists. These quasiparticles are a generalization of bosons and fermions and cannot be clearly assigned to one of the groups. Their name comes from the English word any – “any, everyone.” Anyons have characteristics that other particles do not have: for example, they can have fractional charges and fractional quantum statistics that preserve the “memory” of interactions with other quasiparticles.
“Anyons only exist as collective excitations of electrons under special circumstances,” says study co-author Michael Manfra. – But they really have these obviously unusual properties <…>. It’s funny, because how can they have less charge than the elementary charge of an electron? But it is. ”
For a long time, the existence of anyons remained only a theory. But in 2005, physicists from Stony Brook University in New York State were able to identify several events caused by the interference of these quasiparticles on a special interferometer. The new work provides even more experimental confirmation of the existence of anyions.
The researchers managed to achieve conditions for the manifestation of quasiparticles by directing electrons along a kind of “labyrinth” etched in a nanoscale interferometer made of gallium arsenide and aluminum-gallium arsenide. Thus, the movement of particles was limited to two-dimensional space. In this case, a powerful magnetic field with an induction of 9 T was applied to the interferometer and cooled to 10 millikelvin. The resulting picture of particle interference – the scientists called it “pajama diagram” – indicated the appearance of anyions.
The next step in the study of anyions will be the creation of more complex interferometers. “<…> We will be able to control the location and number of quasiparticles in the chamber,” says lead author of the study, James Nakamura. “Then we will be able to change the number of quasiparticles inside the interferometer upon request and change the interference pattern at our discretion.”
The work of American researchers can be useful for creating productive quantum computers. However, the authors of the study believe that this is primarily an important step in theoretical quantum physics and other proof that the quantum world is very strange.
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