Figure 1

(Color online) Layout of the experimental setup. The two-path optical device acts only on photon $A$. Detectors ${\mathrm{D}}_{\mathrm{A}}$ and ${\mathrm{D}}_{\mathrm{B}}$ perform coincidence measurements.Reuse & Permissions

Figure 2

Experimental data and theoretical prediction (solid line) in the linear entropy-tangle plane. The gray region represents unphysical states and it is bounded from below by MEMSs (dashed curve). The lower dot-dashed curve represents Werner states. The horizontal (dotted) line at $T=4∕9$ separates MEMS I (above) from MEMS II (below). Stars denote MEMS I states ${\rho }_{\star }$ that have the same linear entropy as the measured states ${\rho }_{\mathrm{I}}^{\mathrm{expt}}$ (i.e., the experimental points above the line $T=4∕9$). All measured data follow very well the theoretical curve.Reuse & Permissions