title: On-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits.
abstract: A consequent tendency toward high-performance quantum information processing is to develop the fully integrated photonic chip. Here, we report the on-chip generation and manipulation of entangled photons based on reconfigurable lithium-niobate waveguide circuits. By introducing a periodically poled structure into the waveguide circuits, two individual photon-pair sources with a controllable electro-optic phase shift are produced within a Hong-Ou-Mandel interferometer, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9±0.9% visibility Hong-Ou-Mandel interference. The photon flux reaches ∼1.4×10(7)  pairs nm-1 mW-1. The whole chip is designed to contain nine similar units to produce identical photon pairs spanning the telecom C and L band by the flexible engineering of nonlinearity. Our work presents a scenario for on-chip engineering of different photon sources and paves the way to fully integrated quantum technologies.
authors.affiliation: National Laboratory of Solid State Microstructures and College of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: H
authors.initials: H
authors.lastname: Jin
authors.affiliation: Beijing Institute of Aerospace Control Devices, Beijing 100094, China.
authors.forename: F M
authors.initials: FM
authors.lastname: Liu
authors.affiliation: National Laboratory of Solid State Microstructures and College of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: P
authors.initials: P
authors.lastname: Xu
authors.affiliation: Beijing Institute of Aerospace Control Devices, Beijing 100094, China.
authors.forename: J L
authors.initials: JL
authors.lastname: Xia
authors.affiliation: National Laboratory of Solid State Microstructures and College of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: M L
authors.initials: ML
authors.lastname: Zhong
authors.affiliation: National Laboratory of Solid State Microstructures and College of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Beijing Institute of Aerospace Control Devices, Beijing 100094, China.
authors.forename: J W
authors.initials: JW
authors.lastname: Zhou
authors.affiliation: Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Gong
authors.affiliation: Beijing Institute of Aerospace Control Devices, Beijing 100094, China.
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures and College of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
authors.forename: S N
authors.initials: SN
authors.lastname: Zhu