Quantum nonlinear optics with counter-propagating photons
Abstract
Realizing strong interactions between individual photons is a cornerstone for advancing photonic quantum computing and quantum nonlinear optics. Here, we experimentally demonstrate strong interactions between counter-propagating photons mediated by Rydberg polaritons, achieving a record-long anti-correlation range exceeding . This extended range enables the use of photon pulses that are long enough to fit within the polariton bandwidth, yet short enough to remain within the interaction range. Under these conditions, we observe complete photon blockade of entire pulses, tunable by the pulse timing, thus demonstrating the potential for controlled, deterministic operations. Extending to the three-photon regime, we observe enhanced interactions when a photon encounters two counter-propagating photons. Our results, supported by analytical theory and rigorous numerical simulations, establish counter-propagating Rydberg polaritons as a powerful platform for engineering interactions in quantum light fields.
Cite
@article{arxiv.2506.01124,
title = {Quantum nonlinear optics with counter-propagating photons},
author = {Bankim Chandra Das and Ashley Harkavi and Aditya Prakash and Ariel Nakav and Lee Drori and Ofer Firstenberg},
journal= {arXiv preprint arXiv:2506.01124},
year = {2025}
}
Comments
The first three authors contributed equally to this work. 10 pages, 4 figures