Figure 14

The theoretical and experimental results of the mixed state geometric phase in two situations: \(\Omega = 180^{\circ }\) and \(\Omega = 240^{\circ }\). For each situation, five purity values were chosen for the initial mixed state, \(r=[0.26, 0.50, 0.71, 0.87, 0.97]\). For each experimental data point, the experiments were repeated for 5 times and the mean value of the geometric phase was calculated. The error bar indicates the standard deviation of the geometric phase in the 5 repetitions. The theoretical values of the geometric phase are also shown as circles (\(\Omega = 180^{\circ }\)) and diamonds (\(\Omega = 240^{\circ }\)) in the figure