Quantum-state creation in nonlinear-waveguide arrays

Many photonic quantum information tasks employ single photons and linear transformations to create and manipulate quantum states of light to process information. Integrated optical systems have become useful platforms to perform these tasks. New technologies introduce new possible processes available for multimode quantum operations. Here we explore one such setup, motivated by current experiments, which is a nonlinear-waveguide array system operating in a regime of nondegenerate-frequency down-converted photons. This allows one photon to act as a herald for the other photon, which is created in a superposition of the individual waveguide channels. We demonstrate this setup???s ability to generate highly nonclassical states, such as N-photon Fock states and NOON states.

Automated summary

Many photonic quantum information tasks use single photons and linear transformations for processing information. Integrated optical systems provide useful platforms for these tasks. Nonlinear-waveguide array systems are new technologies that enable multimode quantum operations and can generate highly nonclassical photon states.