 Kramers–Wannier duality

Kramers--Wannier duality exchanges order variables with domain-wall or disorder variables. In multiple dimensions it naturally appears as a tensor-network map with a nontrivial symmetry-sector kernel.

Kramers–Wannier duality is a concept from statistical mechanics and condensed matter physics that describes a relationship between two statistical systems, particularly in the context of lattice models. It was originally discovered in the context of the two-dimensional Ising model, but it applies more broadly to other statistical systems as well.