Fig. 5: Quantum state tomography in the \(\{\left|00\right\rangle,\left|11\right\rangle \}\) basis (Φ configuration).
From: Programmable frequency-bin quantum states in a nano-engineered silicon device
Columns from left to right refer respectively to states: \(\left|00\right\rangle\), \(\left|11\right\rangle\), \(\left|{\Phi }^{+}\right\rangle\), and \(\left|{\Phi }^{-}\right\rangle\). a–d Device pumping scheme for each of the generated state. The path covered by the pump laser is highlighted in red. The generation rings A and B are selectively addressed by acting on the tunable MZI, while the relative phase of the pump is varied through a thermal phase shifter. e–h Real and g–l imaginary part of the reconstructed density matrices for each of the generated states, estimated through the maximum-likelihood method. F, P, and EF indicate, respectively, fidelity, purity, and entanglement of formation of each reconstructed state.
