Sometimes, two dimensions are better than three.
In the three-dimensional world we live in, there are two classes of elementary particles: bosons and fermions. But in two dimensions, theoretical physicists predict, there’s another option: anyons. Now, scientists report new evidence that anyons exist and that they behave unlike any known particle. Using a tiny “collider,” researchers flung presumed anyons at one another to help confirm their identities, physicists report in the April 10 Science.
If the researchers had been colliding antisocial fermions, the particles would have gone their separate ways after the collision. Bosons, on the other hand, would tend to clump at same exit. In the experiment, the researchers saw clumping, but the amount of clumping, and how it changed as the scientists varied the rate at which anyons were sent into the collider, was consistent with theoretical predictions for anyons.
When anyons swap places or loop around one another, physicists predict, the quasiparticles’ quantum states are altered. Identifying this process, known as braiding, would more fully clinch the case for the existence of anyons, says physicist Chetan Nayak of Microsoft Quantum and the University of California, Santa Barbara.
