Fig. 2: Performance of the network in learning one-to-one mapping of quantum states.
From: Universal logical quantum photonic neural network processor via cavity-assisted interactions
a State fidelity as a function of iteration number for a sample of 100 Haar-random multi-photon quantum states. The fidelity of the 2, 3, and 4-photon states approaches unity within 2000 iterations. The inset illustrates the distribution of learned state fidelities. Increasing the number of photons increases the difficulty in learning the target state, resulting in a decrease in the mean fidelity \(\bar{F}\). b State infidelity as a function of the depth of the network for the 4-photon N00N state under the influence of component imperfections. Increasing the depth of the network increases the fidelity, denoted by the black line. The green and blue distributions correspond to the distribution of state infidelity when the beam-splitter error σ is 0.001 and 0.01, respectively. c Distribution of state infidelity as a function of beam-splitter error σ in the Mach-Zehnder Interferometer (MZI). Increasing the error σ increases the mean infidelity, as well as the distribution of state fidelities.
