Quantum-state creation in nonlinear-waveguide arrays

Abstract

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 non-degenerate-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.