A unified diagrammatic approach to topological fixed point models

Understand

We introduce a systematic mathematical language for describing fixed point models and apply it to the study to topological phases of matter.

• The framework is reminiscent of state-sum models and lattice topological quantum field theories, but is formalised and unified in terms of tensor networks.
• In contrast to existing tensor network ansatzes for the study of ground states of topologically ordered phases, the tensor networks in our formalism represent discrete path integrals in Euclidean space-time.
• This language is more directly related to the Hamiltonian defining the model than other approaches, via a Trotterization of the respective imaginary time evolution.