Correlating photons using the collective nonlinear response of atoms weakly coupled to an optical mode
Abstract
Photons in a nonlinear medium can repel or attract each other, resulting in strongly correlated quantum manybody states^{1,2}. Typically, such correlated states of light arise from the extreme nonlinearity granted by quantum emitters that are strongly coupled to a photonic mode^{2,3}. However, unavoidable dissipation (such as photon loss) blurs nonlinear quantum effects when such approaches are used. Here, we generate strongly correlated photon states using only weak coupling and taking advantage of dissipation. An ensemble of noninteracting waveguidecoupled atoms induces correlations between simultaneously arriving photons through collectively enhanced nonlinear interactions. These correlated photons experience less dissipation than the uncorrelated ones. Depending on the number of atoms, we experimentally observe strong photon bunching or antibunching of the transmitted light. This realization of a collectively enhanced nonlinearity may turn out to be transformational for quantum information science and opens new avenues for generating nonclassical light, covering frequencies from the microwave to the Xray regime.
 Publication:

Nature Photonics
 Pub Date:
 2020
 DOI:
 10.1038/s415660200692z
 arXiv:
 arXiv:1911.09701
 Bibcode:
 2020NaPho..14..719P
 Keywords:

 Quantum Physics
 EPrint:
 9 pages, 5 figures