Fig. 1: Results of estimation error for qubit.
From: Direct estimation of quantum coherence by collective measurements
Mean errors for estimating ℓ1-norm coherence in a and relative entropy coherence in b for a family of qubit states with different measurement schemes. The states have the form \(\left|\Psi \right\rangle =\sin \theta \left|0\right\rangle +\cos \theta \left|1\right\rangle\) with θ ranging from 0 to π/2. In a, the performances of CMS (numerical simulation and experiment); σx, σy measurement (simulation); two-step adaptive measurements (simulation); and tomography (simulation) are shown for comparison. In b, the performances of CMS (numerical simulation and experiment) and tomography (simulation) are shown for comparison. The sample size is N = 1200. Each data point is the average of 1000 repetitions, and the error bar denotes the standard deviation.
