Two physicists (a female and male) working on a lab experiment

ALP Seminar: Correlating photons using the collective nonlinear response of atoms weakly coupled to an optical mode

03 Jun 2024
Seminars and colloquia
Simpkins Lee
Beecroft Building

Prof. Arno Rauschenbeutel (Humboldt University, Berlin)

Seminar series
ALP seminar
Knowledge of physics?
Yes, knowledge of physics required
For more information contact


Non-classical states of light – such as single photons or entangled photon pairs – are a key resource for quantum science and technology, and their generation is a very active area of research. In this context, it has been predicted that resonant laser light, when simply transmitted through an ensemble of two-level emitters, can evolve into a quantum-correlated state of light [Phys. Rev. Lett. 121, 143601 (2018)]. According to this work, the weak nonlinear response of the individual emitters can be collectively enhanced, leading to a correlated transport of photons through the ensemble. Using laser-cooled atoms that are trapped and optically interfaced with a nanophotonic waveguide, this effect has recently been demonstrated by our group. Depending on the experimental parameters, the output light exhibits photon bunching and anti-bunching [Nat. Photonics 14, 719 (2020); Phys. Rev. Lett. 131, 183601 (2023)] or quadrature squeezing [Phys. Rev. Lett. 127, 123602 (2021)], while maintaining excellent coherence properties and indistinguishability. My talk will introduce this new mechanism of nonlinear photon transport and discuss its future applications.