Non-abelian anyons are exotic quasiparticles with non-commutative braiding statistics in quantum systems.Non-abelian anyons are quasiparticles that exist only in two-dimensional systems and obey exotic quantum statistics. Unlike ordinary particles (fermions and bosons), swapping two anyons does not just multiply the quantum state by a simple phase factor — the order of swaps matters, and the final state depends on the braiding history. This non-commutative property is the key to their potential use in topological quantum computing, where quantum information is encoded in the braiding patterns of these particles, making it inherently protected from local noise.
The concept of anyons was introduced by Frank Wilczek in 1982, and the idea of non-abelian anyons was developed by Gregory Moore and Nicholas Read in 1991, and independently by Xiao-Gang Wen. The theoretical framework was further advanced by Alexei Kitaev in 1997, who proposed concrete physical systems for their realization.
In two dimensions, the path of a particle around another can be continuously deformed in ways impossible in three dimensions, allowing for anyonic statistics. For non-abelian anyons, the Hilbert space of the system has a degeneracy: multiple distinct quantum states share the same energy. Braiding two anyons performs a unitary transformation within this degenerate subspace, effectively performing a quantum gate. The result of a sequence of braids depends on their order, hence 'non-abelian' — the operations do not commute.
Non-abelian anyons are the foundation of topological quantum computers, where quantum information is stored in the braiding history of quasiparticles, offering inherent error resistance. They are also studied in fractional quantum Hall systems and in proposals using Majorana fermions in superconducting nanowires.
The braiding of non-abelian anyons is mathematically equivalent to the operation of a quantum computer, meaning that if you can control their braiding, you can perform any quantum computation.








