Figure 4

Performance obtained with the optical implementation of Fig. 3. The bar graph at the top corresponds to the case in which the prepared qubit in \(q[0]\) is \(\vert 0 \rangle \), while in the case of preparing a \(\vert 1 \rangle \), its respective bar graph is at the bottom of this figure. The pink bars correspond to the horizontal polarization performances of qubits \(q[0]\) and \(q[1]\), while the blue bars correspond to their vertical pola-rization performances. In qubit \(q[1]\) on Bob’s side, a performance degradation can be distinguished which will be compensated in Sect. 3.1