Two-photon path-entangled states in multi-mode waveguides

TL;DR

This paper demonstrates that multi-mode waveguides can coherently manipulate two-photon path-entangled states, acting as nearly-ideal multi-port beam splitters at the quantum level, enabling diverse entangled and separable states.

Contribution

It experimentally shows that multi-mode waveguides can serve as effective quantum beam splitters for two-photon entangled states, expanding quantum photonics capabilities.

Findings

Multi-mode waveguides perform as nearly-ideal multi-port beam splitters.

They can generate a variety of entangled and separable two-photon states.

Output correlations depend on input phase, demonstrating coherent control.

Abstract

We experimentally show that two-photon path-entangled states can be coherently manipulated by multi-mode interference in multi-mode waveguides. By measuring the output two-photon spatial correlation function versus the phase of the input state, we show that multi-mode waveguides perform as nearly-ideal multi-port beam splitters at the quantum level, creating a large variety of entangled and separable multi-path two-photon states.