Topics: Particle Physics, Quantum Computer, Quantum Mechanics, Theoretical Physics
Flatland: “The book used the fictional two-dimensional world of Flatland to comment on the hierarchy of Victorian culture, but the novella’s more enduring contribution is its examination of dimensions.” Source: Wikipedia
After decades of exploration in nature’s smallest domains, physicists have finally found evidence that anyons exist. First predicted by theorists in the early 1980s, these particle-like objects only arise in realms confined to two dimensions, and then only under certain circumstances — like at temperatures near absolute zero and in the presence of a strong magnetic field.
Physicists are excited about anyons not only because their discovery confirms decades of theoretical work, but also for practical reasons. For example: Anyons are at the heart of an effort by Microsoft to build a working quantum computer.
This year brought two solid confirmations of the quasiparticles. The first arrived in April, in a paper featured on the cover of Science, from a group of researchers at the École Normale Supérieure in Paris. Using an approach proposed four years ago, physicists sent an electron gas through a teeny-tiny particle collider to tease out weird behaviors — especially fractional electric charges — that only arise if anyons are around. The second confirmation came in July, when a group at Purdue University in Indiana used an experimental setup on an etched chip that screened out interactions that might obscure the anyon behavior.
MIT physicist Frank Wilczek, who predicted and named anyons in the early 1980s, credits the first paper as the discovery but says the second lets the quasiparticles shine. “It’s gorgeous work that makes the field blossom,” he says. Anyons aren’t like ordinary elementary particles; scientists will never be able to isolate one from the system where it forms. They’re quasiparticles, which means they have measurable properties like a particle — such as a location, maybe even a mass — but they’re only observable as a result of the collective behavior of other, conventional particles. (Think of the intricate geometric shapes made by group behavior in nature, such as flocks of birds flying in formation or schools of fish swimming as one.)
The known universe contains only two varieties of elementary particles. One is the family of fermions, which includes electrons, as well as protons, neutrons, and the quarks that form them. Fermions keep to themselves: No two can exist in the same quantum state at the same time. If these particles didn’t have this property, all matter could simply collapse to a single point. It’s because of fermions that solid matter exists.
The rest of the particles in the universe are bosons, a group that includes particles like photons (the messengers of light and radiation) and gluons (which “glue” quarks together). Unlike fermions, two or more bosons can exist in the same state at the same time. They tend to clump together. It’s because of this clumping that we have lasers, which are streams of photons all occupying the same quantum state.
Physicists prove the existence of two-dimensional particles called ‘anyons’, Stephen Omes, Astronomy (December 2020)