In this seminar, we will discuss the conditional measurement of field amplitudes by a nonclassical photon sequence in the Jaynes-Cummings (JC) model under multiphoton operation. We do so by employing a correlator of immediate experimental relevance to reveal a distinct quantum evolution in the spirit of [G. T. Foster et al., Phys. Rev. Lett. 85, 3149 (2000)],
relying on the complementary nature of the pictures obtained from different unravelings of the JC master equation. We demonstrate that direct photodetection entails a conditioned separation of timescales, a quantum beat and a semiclassical oscillation, produced by the coherent light-matter interaction in its strong-coupling limit. We single the quantum beat out in the analytical expression for the waiting-time distribution, pertaining to the particle nature of the scattered light, and find a negative spectrum of quadrature amplitude squeezing, characteristic of its wave nature. Finally, we jointly detect the dual aspects of the emitted radiation via the wave-particle correlator, showing an asymmetric regression of fluctuations to the steady state which depends on the quadrature amplitude being measured. The individual realizations thus obtained allow the experimenter to access the distribution and statistics of the light field in a regime where photon blockade persists [H. J. Carmichael, Phys. Rev. X. 5, 031028 (2015)].
