Figure 3
From: Achieving quantum precision limit in adaptive qubit state tomography
Precision limit with respect to the MSE. Experimental results of standard, adaptive and known-state tomography are shown together with the theoretical MSE of the standard tomography and the GM bound. Here s is the length of the Bloch vector. In the experiment, N=9,000 and N1=3,000; each data point averages over 4,000 repetitions and the error bar denotes the s.d. of the mean. The MSE of the standard tomography is lower than the theoretical value when the purity of the state is sufficiently high (depending on N) because the estimator is biased due to the influence of the boundary of the state space.
