Fig. 2: The 15 elements of \({\overline{\boldsymbol{\mathcal{S}}}}\).
From: Optimal two-qubit circuits for universal fault-tolerant quantum computation
These are the images of the 15 elements of \({\mathcal{S}}\) under the action of the SU(4) ≅ Spin(6) isomorphism. Each matrix may be associated with a unique pairing of rows and columns.
