Fig. 1
From: High-dimensional optical quantum logic in large operational spaces
Illustration of the scheme. Two qudits encoded in d time bins and frequency bins in a single photon, going through a deterministic quantum process. The single photon can be encoded in an arbitrary superposition of different time and frequency bins; the unused time–frequency slots are shown with dashed circles. After the deterministic quantum process operates on the two-qudit state, the orientation of the time–frequency superpositions change to a new two-qudit state
