4d $\mathcal{N}=2$ S-folds

We propose a generalization of S-folds to 4d $\mathcal{N}=2$ theories. This
construction is motivated by the classification of rank one 4d $\mathcal{N}=2$
super-conformal field theories (SCFTs), which we reproduce from D3-branes
probing a configuration of $\mathcal{N}=2$ S-folds combined with 7-branes. The
main advantage of this point of view is that realizes both Coulomb and Higgs
branch flows and allows for a straight forward generalization to higher rank
theories.