Effective two-level approximation of a multi-level system driven by coherent and incoherent fields

Abstract

The numerical simulation of multiple scattering in dense ensembles is the mostly adopted solution to predict their complex optical response. While the scalar and vectorial light mediated interactions are accurately taken into account, the computational complexity still limits current simulations to the low saturation regime and ignores the internal structure of atoms. Here, we propose to go beyond these restrictions, at constant computational cost, by describing a multi-level system (MLS) by an effective two-level system (TLS) that best reproduces the coherent and total scattering properties in any saturation regime. The correspondence of our model is evaluated for different experimentally realistic conditions such as the modification of the driving field polarization, the presence of stray magnetic fields or an incoherent resonant electromagnetic field background. The trust interval of the model is quantified for the D2-line of 87Rb atoms but it could be generalized to any closed transition of a multi-level quantum system.

11 pages, 6 figures

References in corpus (7)

• Strong saturation absorption imaging of dense clouds of ultracold atoms
• Collective shift in resonant light scattering by a one-dimensional atomic chain
• Transmission of near-resonant light through a dense slab of cold atoms
• Modified Bloch-Redfield Master Equation for Incoherent Excitation of Multilevel Quantum Systems
• Secular vs. Non-secular Redfield Dynamics and Fano Coherences in Incoherent Excitation: An Experimental Proposal
• Collective Excitation Dynamics of a Cold Atom Cloud
• Comparison of three approaches to light scattering by dilute cold atomic ensembles

Cited by in corpus (3)

• Spatial calibration of high-density absorption imaging
• In situ subwavelength microscopy of ultracold atoms using dressed excited states
• Bimodal phase transition in a periodically modulated $\Lambda$-type three-level system