# Generation of path-encoded Greenberger-Horne-Zeilinger states

## TL;DR

This paper proposes a method to generate three-photon GHZ states using path encoding in integrated optical circuits, potentially improving efficiency with microring resonators and offering a practical implementation approach.

## Contribution

It introduces a novel path-encoded GHZ state generation scheme and suggests enhancements via microring resonators for better efficiency.

## Key findings

- Path encoding of GHZ states demonstrated
- Integrated optical circuit implementation proposed
- Efficiency can be improved with microring resonators

## Abstract

We study the generation of Greenberger-Horne-Zeilinger (GHZ) states of three path-encoded photons. Inspired by the seminal work of Bouwmeester et al. [1] on polarization-entangled GHZ states, we find a corresponding path representation for the photon states of an optical circuit, identify the elements required for the state generation, and propose a possible implementation of our strategy. Besides the practical advantage of employing an integrated system that can be fabricated with proven lithographic techniques, our example suggests that it is possible to enhance the generation efficiency by using microring resonators.