Collective excitation dynamics of a cold atom cloud

Quantum collective effects in a dilute cloud of two-level atoms interacting with a classical light

“…10,61,66,[68][69] In this chapter we present a detailed study of the switch-on dynamics in the linear optics limit and show, with simulations and experimental comparison, that a first extension of the CD model beyond linear optics is a nonlinear MF model. 22 We also present preliminary results with the QPC model demonstrating the role of quantum correlations in the subradiant decay dynamics of the atomic excitation.…”

“…This procedure and the mean over realizations reduces the noise and fluctuations in the signal and allows to attenuate the contributions from unwanted photons. Source: Adapted from ESPIRITO SANTO et al 22 In Fig. 18 we compare the experimental results with numerical simulations for the time-dependent field dynamics.…”

“…1. Source: Adapted from ESPIRITO SANTO et al 22 It is a challenge to treat a quantum many-body problem due to the high number of degrees of freedom and many emission processes occurring concurrently, which result in an untractable set of differential equations for more than a dozen atoms. In that sense, a series of approximations are necessary to address the system in specific conditions.…”

“…where Γ N is the collective decay rate and Ω N the generalized Rabi frequency of the effective mode. Source: Adapted from ESPIRITO SANTO et al 22 In Fig. 19 we have fitted the Eq.…”

“…In Chapter 4 and 5 we explore experimentally accessible observables. For the radiated field intensity, we obtain results that shows cooperative phenomenon in the switch-on dynamics 22 , in collaboration with an experimental group. We also show that, increasing the saturation parameter of the system, the linear optics regime is no longer valid: We enter in the non-linear and quantum regime, in which the mean-field equations and quantum pair correlation method can be applied successfully.…”