Observation of a three-photon bound state

ORAL

Abstract

Bound states of massive particles, be it in the form of nucleons, atoms or molecules, are ubiquitous, and constitute the bulk of the visible world around us. In contrast, photon-photon interactions are weak and need to be specifically engineered in the form of nonlinear optical media. Here we report the observation of a three-photon bound state inside a quantum nonlinear optical medium. The strong photon-photon interaction is achieved by coupling the light to highly excited, strongly interacting Rydberg states in a cold atomic gas. The photonic trimer, which can be viewed as a quantum soliton, is observed via bunching and a strongly nonlinear phase in the three-photon correlation function of the emerging light. The observations are quantitatively described by an effective field theory of Rydberg-induced photon-photon interactions, and agree with direct numerical simulations. This work paves the way towards the realization, understanding, and control of strongly interacting quantum gases of light.

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Authors

  • Qiyu Liang

    • Massachusetts Institute of Technology

  • Sergio Cantu

    • Massachusetts Institute of Technology

  • Aditya Venkatramani

    • Harvard University

  • Travis Nicholson

    • Massachusetts Institute of Technology

  • Michael Gullans

    • Joint Quantum Institute, NIST/University of Maryland

  • Alexey Gorshkov

    • Joint Quantum Institute, NIST/University of Maryland
    • Joint Quantum Institute; Joint Center for Quantum Information and Computer Science

  • Jeff Thompson

    • Princeton University

  • Cheng Chin

    • James Franck Institute, Enrico Fermi Institute, and Department of Physics, University of Chicago
    • University of Chicago

  • Mikhail Lukin

    • Harvard University
    • Harvard Univ

  • Vladan Vuletic

    • Department of Physics, MIT
    • Massachusetts Institute of Technology