Exactly solvable spin-1/2 model on a honeycomb lattice. Z₂ fluxes through plaquettes define vortex sectors. Click plaquettes to insert/remove π-flux vortices (non-Abelian anyons in phase B).
Kitaev (2003): the honeycomb spin model maps to free Majorana fermions coupled to a Z₂ gauge field. Each hexagonal plaquette has a conserved flux W_p=±1. Phase A (gapped, abelian anyons) when one coupling dominates; Phase B (gapless, non-abelian anyons with magnetic field) when all equal.