Scalable multimode entanglement based on efficient squeezing of propagation eigenmodes

TL;DR

This paper presents a simple, robust protocol for generating large-scale spatial multipartite entanglement in optical waveguide arrays, advancing quantum networks with efficient, scalable continuous-variable entanglement.

Contribution

It introduces a novel method leveraging phase-matching in monolithic waveguide arrays to produce scalable multipartite entanglement without precise parameter tuning.

Findings

Demonstrates generation of large multipartite entangled states in waveguide arrays.

Protocol is robust and does not depend on specific coupling or length.

Applicable for multimode quantum networks.

Abstract

Continuous-variable encoding of quantum information in the optical domain has recently yielded large temporal and spectral entangled states instrumental for quantum computing and quantum communication. We introduce a protocol for the generation of spatial multipartite entanglement based on phase-matching of a propagation eigenmode in a monolithic photonic device: the array of quadratic nonlinear waveguides. We theoretically demonstrate in the spontaneous parametric downconversion regime the generation of large multipartite entangled states useful for multimode quantum networks. Our protocol is remarkably simple and robust as it does not rely on specific values of coupling, nonlinearity or length of the sample.