Simple analytical model describing the collective nonlinear response of an ensemble of two-level emitters weakly coupled to a waveguide
Year: 2026
Authors: Schemmer M., Cordier M., Pache L., Schneeweiss P., Volz J., Rauschenbeutel A.
Autors Affiliation: Humboldt Univ, Dept Phys, Berlin, Germany; Consiglio Nazl Ric CNR, Ist Nazl Ott, I-50019 Sesto Fiorentino, Italy.
Abstract: We model and investigate the collective nonlinear optical response of an ensemble of two-level emitters that are weakly coupled to a waveguide featuring a single spatial mode. Our approach generalizes the insight that photon-photon correlations in the light scattered by a single two-level emitter result from two-photon interference to the case of many emitters. Using our model, developed for coherent driving in the weak-saturation regime, we study different configurations for probing the nonlinear response of the ensemble, e.g., through the waveguide or via external illumination, and derive analytical expressions for the second-order quantum coherence function, g(2 )(t ), as well as for the squeezing spectrum of the output light in the waveguide, S9 (w). For the transmission of resonant guided light, we recover the same predictions as previously made with more involved theoretical models when analyzing experimental results regarding g(2)(t) [Prasad et al., Nat. Photon. 14, 719 (2020)] and S9(w) [Hinney et al., Phys. Rev. Lett. 127, 123602 (2021)]. We also study the transmission of light that is detuned from the transition of the two-level emitter, a situation that we recently studied experimentally [Cordier et al., Phys. Rev. Lett. 131, 183601 (2023)]. Our model predictions show how the collectively enhanced nonlinear response of weakly coupled emitters can be harnessed to generate nonclassical states of light using ensembles ranging from a few to many emitters.
Journal/Review: PHYSICAL REVIEW A
Volume: 114 (1) Pages from: 13711-1 to: 13711-16
More Information: We gratefully thank S. Mahmoodian, K. Hammerer, and A. Sorensen for discussions and feedback. M.S. acknowledges funding from the Italian Ministry of University and Research, in the framework of the National Recovery and Resilience Plan (NRRP) for funding Project No. MSCA_0000048. M.C. and M.S. acknowledge support from the European Commission (Marie Sklodowska-Curie IF Grants No. 101029304 and No. 896957) . We acknowledge funding by the Alexander von Humboldt Foundation in the framework of the Alexander von Humboldt Professorship endowed by the Federal Ministry of Education and Research, as well as funding by the European Commission under the project DAALI (No. 899275) , and by the Einstein Foundation (Einstein Research Unit on Quantum Devices) .KeyWords: Resonance Fluorescence; Quantum; ScatteringDOI: 10.1103/svb4-98c2
