Fig. 4: Diagram of the full heralding protocol and timing.
From: Spin-optomechanical cavity interfaces by deep subwavelength phonon-photon confinement
Schematic of the full protocol depending on the (a) absence or (b) presence of a photon click on the photo-detectors at t = tC. (c) Map of all possible quantum trajectories.We start with N trajectories. Out of them, there is a photon click in x1 of them. After getting a click, there are three possibilities, where events a, b and b1 correspond to the three collapse operators described in section 2.3. The spin-phonon swap is performed on all the brown trajectories, but ideally only the green ones are the good trajectories, which means that the red ones, lead to the infidelity of our heralding plus swap protocol. Using the trajectory approach, we can easily estimate, Pherald = \(\frac{{x}_{1}}{N}\) and pgood−traj = \(\frac{{x}_{5}}{{x}_{1}}\).
