Fig. 4: Logical controlled phase gate schematic and performance.
From: Universal logical quantum photonic neural network processor via cavity-assisted interactions
a Circuit implementation of the logical controlled phase gate with an encoding and decoding step that rotates the logical states into the fock basis and vice-versa. b Gate fidelity of the logical controlled phase gate illustrated in (a) on the 5-photon two-mode binomial code. A network that is 10 layers deep (5 layers in the encoding and decoding steps each) is able to perform the transformation to a fidelity >99.99%. The green and blue histograms indicate the distribution of infidelities when splitter errors are σ = 0.001 and σ = 0.01, respectively, with worst-case fidelities on the order of ~10%.
