Excitations in strict 2-group higher gauge models of topological phases

Understand

We consider an exactly solvable model for topological phases in (3+1)d whose input data is a strict 2-group.

• This model, which has a higher gauge theory interpretation, provides a lattice Hamiltonian realisation of the Yetter homotopy 2-type topological quantum field theory.
• The Hamiltonian yields bulk flux and charge composite excitations that are either point-like or loop-like.
• Applying a generalised tube algebra approach, we reveal the algebraic structure underlying these excitations and derive the irreducible modules of this algebra, which in turn classify the elementary excitations of the model.