Entanglement entropy at CFT junctions

Understand

We consider entanglement through permeable junctions of $N$ $(1+1)$-dimensional free boson and free fermion conformal field theories.

• In the folded picture we constrain the form of the general boundary state.
• We calculate replicated partition functions with interface operators inserted in the partially-folded picture, from which the entanglement entropy is calculated.
• The functional form of the universal and constant terms are the same as the $N=2$ case, depending only of the total transmission of the junction and the unit volume of the zero mode lattice.