Figure 3: Back-action vector maps.

(a) An arbitrary initial state in the X–Z plane of the Bloch sphere is prepared by heralding on the average homodyne signal . After heralding, we digitize the signal for an additional 40 ns to obtain dV. Finally, we use quantum state tomography to examine the conditional back-action based on the value of dV. (b) Histogram of the signals dV which we separate into positive or negative dV. The back-action imparted on the emitter for negative (c) or positive (d) values of dV is depicted by an arrow at different locations in the X–Z plane of the Bloch sphere.