2024/09/02 by Orazio Scarlatella, Scarlatella, Orazio, Nigel R. Cooper +1 · 2 citations
Engineering · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Near-Field Optical Microscopy #Quantum Gases (cond-mat.quant-gas) #Quantum Physics (quant-ph) #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2409.01386
openalex publication_date 2024/09/02 · openalex created_date 2024/09/29 · openalex updated_date 2026/07/31
Harnessing the nonlinear response of a medium is essential for applications including frequency conversion and light amplification, as well as for the generation of quantum many-body correlations of light or matter. However, achieving these effects typically requires high drive intensities and thick samples, which induce undesired heating effects that typically suppress quantum correlations. In this work, we demonstrate that atom-thin arrays of quantum emitters exhibit a robust nonlinear response even at arbitrarily weak drive intensities. This discovery challenges the long-held assumption that weakly driven ensembles behave classically; instead, we reveal that subradiant states provide a dominant nonlinear contribution that persists in the low-intensity limit. Using a Dynamical Mean-Field Theory (DMFT) approach, we predict that these nonlinearities generate a quantum-correlated steady state composed of interacting pairs of subradiant excitations, characterized by long-range correlations and multi-mode squeezing. Our findings establish a new frontier for nonlinear quantum optics at minimal power, and provide a scalable protocol for preparing multimode squeezing, offering potential for applications in quantum metrology.