Few-photon transport via a multimode nonlinear cavity: theory and applications

TL;DR

This paper investigates how a multimode nonlinear optical cavity coupled to a waveguide can facilitate nonclassical photon transport effects like photon blockade and phase shifts, with implications for quantum information processing.

Contribution

It introduces a theoretical framework using Feynman diagrams to analyze one- and two-photon scattering in a multimode nonlinear cavity, revealing new quantum photonic effects.

Findings

Demonstrates photon blockade in the system

Shows achievable $\pi$-phase shifts via quantum interference

Provides a scattering matrix approach for multimode nonlinear cavities

Abstract

Few-photon transport via waveguide-coupled local quantum systems has attracted extensive theoretical and experimental studies. Most of the study has focused on atomic or atomic-like local quantum systems due to their strong light-matter interaction useful for quantum applications. Here, we study few-photon transport via a waveguide-coupled multimode optical cavity with second-order bulk nonlinearity. We develop a Feynman diagram approach and compute the scattering matrix of the one- and two-photon transport. Based on the calculated scattering matrix, we show highly nonclassical photonic effects, including photon blockade and $\pi-$conditional phase shift, are achievable in the waveguide-coupled multimode optical cavity system via quantum interference and linear response engineering. Our results might lead to significant applications of quantum photonic circuits in all-optical quantum information processing and quantum network protocols.