Cavity-QED models of switches for attojoule-scale nanophotonic logic

TL;DR

This paper develops quantum optical models for cavity QED-based optical switches capable of operating at attojoule energy scales, demonstrating their potential for low-power nanophotonic logic applications.

Contribution

It introduces a quantum input-output model for cavity QED switches and proves their convergence to a simple scattering matrix in a strong coupling limit, supported by numerical simulations.

Findings

Models converge to a scattering matrix in strong coupling limit

Switching at attojoule energy scales is feasible

Numerical results confirm realistic low-power operation

Abstract

Quantum optical input-output models are described for a class of optical switches based on cavity quantum electrodynamics (cavity QED) with a single multilevel atom (or comparable bound system of charges) coupled simultaneously to several resonant field modes. A recent limit theorem for quantum stochastic differential equations is used to show that such models converge to a simple scattering matrix in a type of strong coupling limit that seems natural for nanophotonic systems. Numerical integration is used to show that the behavior of the pre-limit model approximates that of the simple scattering matrix in a realistic regime for the physical parameters, and that it is possible in the proposed cavity-QED configuration for low power optical signals to switch higher-power signals at attojoule energy scales.