Fig. 4: Stability of the QBER and evolution of the correlation matrix over time.
From: Frequency-bin entanglement-based Quantum Key Distribution
a QBER variations on the X and Z basis as a function of time with (locked) and without (unlocked) active phase compensation. In left-panel, the signal photon propagates along 8 km of fiber spool, while in the right panel along 26 km. b Fidelity between the experimental and the theoretical correlation matrix of the outcomes between the X and Z basis as a function of time. The black(gray) lines indicate the fidelity with the active phase compensation turned on(off). The two insets show the correlation matrix at two different times.
