Fig. 5: Measured four-photon events for the improved Bell-state measurement scheme.
From: Boosted Bell-state measurements for photonic quantum computation
Each bar corresponds to the probability of measuring a specific detector click pattern. The states \(\left\vert {\Psi }^{+}\right\rangle\) and \(\left\vert {\Psi }^{-}\right\rangle\) can be correctly identified with a probability of (92.4 ± 0.5)% and (92.7 ± 0.5)%, respectively. The improved scheme leads to measurement results that are exclusive to either \(\left\vert {\Phi }^{+}\right\rangle\) or \(\left\vert {\Phi }^{-}\right\rangle\). These states can be correctly identified with a probability of (46.1 ± 0.8)% and (46.2 ± 0.6)%, respectively.
