Symmetry-resolved entanglement entropy in Wess-Zumino-Witten models

We consider the problem of the decomposition of the Renyi entanglement entropies in theories with a non-abelian symmetry by doing a thorough analysis of Wess-Zumino-Witten (WZW) models. We first consider SU(2)(k) as a case study and then generalise to an arbitrary non-abelian Lie group. We find that at leading order in the subsystem size L the entanglement is equally distributed among the different sectors labelled by the irreducible representation of the associated algebra. We also identify the leading term that breaks this equipartition: it does not depend on L but only on the dimension of the representation. Moreover, a log log L contribution to the Renyi entropies exhibits a universal prefactor equal to half the dimension of the Lie group.

Automated summary

Through a thorough analysis of Wess-Zumino-Witten models, we find that in theories with a non-abelian symmetry, the Renyi entanglement entropy is equally distributed among different sectors at leading order, with a leading term breaking this equipartition depending only on the dimension of the representation. Additionally, a log log L contribution exhibits a universal prefactor equal to half the dimension of the Lie group.