Figure 3
Comparison of the fidelity of Two-qubit density matrix by two fidelity estimation methods: Each point is the average gap between the estimated value and the true fidelity \(F_{true}\) calculated by 100 estimations separately. Black dot represents the estimation by traditional method (direct fidelity estimation), while red dot represents the estimation our optimal fidelity estimation. Error bar is the standard deviation of the estimated gap between the estimated fidelity and true fidelity.
