Versatile Photonic Entanglement Synthesizer in the Spatial Domain

Multimode entanglement is an essential resource for quantum information. Continuous-variable encoding in the optical domain has recently yielded large temporal and spectral entangled states [1] . We present results [2] - [4] that re-establish spatial encoding as a contender in the game of continuous-variable quantum information processing i.e. strategies to generate and engineer multimode entangled states at the outputs of nonlinear waveguide arrays ( Fig. 1a ). Such states are especially interesting because they are by nature distributable in real quantum networks and protocols. In addition, scalability, reconfigurability, subwavelength stability, reproducibility, and low cost make our scheme an appealing quantum technology with respect to bulk-optics-based multipartite-entanglement approaches.