title: Transmission of photonic quantum polarization entanglement in a nanoscale hybrid plasmonic waveguide.
abstract: Photonic quantum technologies have been extensively studied in quantum information science, owing to the high-speed transmission and outstanding low-noise properties of photons. However, applications based on photonic entanglement are restricted due to the diffraction limit. In this work, we demonstrate for the first time the maintaining of quantum polarization entanglement in a nanoscale hybrid plasmonic waveguide composed of a fiber taper and a silver nanowire. The transmitted state throughout the waveguide has a fidelity of 0.932 with the maximally polarization entangled state Φ(+). Furthermore, the Clauser, Horne, Shimony, and Holt (CHSH) inequality test performed, resulting in value of 2.495 ± 0.147 > 2, demonstrates the violation of the hidden variable model. Because the plasmonic waveguide confines the effective mode area to subwavelength scale, it can bridge nanophotonics and quantum optics and may be used as near-field quantum probe in a quantum near-field micro/nanoscope, which can realize high spatial resolution, ultrasensitive, fiber-integrated, and plasmon-enhanced detection.
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Chang-Ling
authors.initials: CL
authors.lastname: Zou
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Xi-Feng
authors.initials: XF
authors.lastname: Ren
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Xiong
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Yong-Jing
authors.initials: YJ
authors.lastname: Cai
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Guo
authors.affiliation: §State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Tong
authors.affiliation: †Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei, 230026, People's Republic of China.
authors.forename: Guang-Can
authors.initials: GC
authors.lastname: Guo
keywords: Surface plasmon polaritons; quantum entanglement; silver nanowire