Fig. 4: Observed quantum interference and reconstructed density matrix.
From: Time-bin entangled Bell state generation and tomography on thin-film lithium niobate
a Two-dimensional histograms correspondent to the four sets of projectors, with the oscillating state marked with a red ellipse. b Collapsed triple coincidences with the interfering state fitted to a Gaussian model and the corresponding oscillatory behaviour highlighted. c, d Tomographic state reconstruction, real and imaginary part, with shaded bars superimposed to the matrices indicating errors obtained via Monte Carlo simulation. e Fidelity, concurrence and single qubit entropy histograms originating from the Monte-Carlo simulation, showing high degree of entanglement and suitability of the device for QKD experiments.
