Figure 3: Density matrix reconstruction through least-squares estimation.
From: Complete tomography of a high-fidelity solid-state entangled spin–photon qubit pair
(a) Real part of the density matrix obtained using the MLE procedure described in the text. The ideal density matrix (ρideal) is overlayed (shaded box). (b) Imaginary part of the density matrix obtained using the MLE procedure described in the text. The ideal density matrix (ρideal) is overlayed (shaded box). (c) Histogram (100,000 runs) of the obtained fidelities using the MLE-reconstruction, taking into account the experimental uncertainties. The mean and median fidelities are over 92%, with standard errors of about 3.2%.
