title: Compact engineering of path-entangled sources from a monolithic quadratic nonlinear photonic crystal.
abstract: An integrated realization of photonic entangled states becomes an inevitable tendency toward integrated quantum optics. Here we report the compact engineering of steerable photonic path-entangled states from a monolithic quadratic nonlinear photonic crystal. The crystal acts as a coherent beam splitter to distribute photons into designed spatial modes, producing the heralded single-photon and appealing beamlike two-photon path entanglement. We characterize the path entanglement by implementing quantum spatial beating experiments. Such a multifunctional entangled source can be further extended to the high-dimensional fashion and multiphoton level, which paves a desirable way to engineering miniaturized quantum light sources.
authors.affiliation: National Laboratory of Solid State Microstructures, College of Physics, and National Center of Microstructures and Quantum Manipulation, Nanjing University, Nanjing 210093, China.
authors.forename: H
authors.initials: H
authors.lastname: Jin
authors.forename: P
authors.initials: P
authors.lastname: Xu
authors.forename: X W
authors.initials: XW
authors.lastname: Luo
authors.forename: H Y
authors.initials: HY
authors.lastname: Leng
authors.forename: Y X
authors.initials: YX
authors.lastname: Gong
authors.forename: W J
authors.initials: WJ
authors.lastname: Yu
authors.forename: M L
authors.initials: ML
authors.lastname: Zhong
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.forename: S N
authors.initials: SN
authors.lastname: Zhu