title: Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information.
abstract: Photonics has become a mature field of quantum information science, where integrated optical circuits offer a way to scale the complexity of the set-up as well as the dimensionality of the quantum state. On photonic chips, paths are the natural way to encode information. To distribute those high-dimensional quantum states over large distances, transverse spatial modes, like orbital angular momentum possessing Laguerre Gauss modes, are favourable as flying information carriers. Here we demonstrate a quantum interface between these two vibrant photonic fields. We create three-dimensional path entanglement between two photons in a nonlinear crystal and use a mode sorter as the quantum interface to transfer the entanglement to the orbital angular momentum degree of freedom. Thus our results show a flexible way to create high-dimensional spatial mode entanglement. Moreover, they pave the way to implement broad complex quantum networks where high-dimensionally entangled states could be distributed over distant photonic chips.
authors: 1] Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna A-1090, Austria [2] Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Boltzmanngasse 3, Vienna A-1090, Austria.
authors: Robert
authors: R
authors: Fickler
authors: 1] Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna A-1090, Austria [2] Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Boltzmanngasse 3, Vienna A-1090, Austria.
authors: Radek
authors: R
authors: Lapkiewicz
authors: 1] Fisica Teorica: Informacio i Fenomens Quantics, Departament de Fisica, Universitat Autonoma de Barcelona, Bellaterra, E-08193 Barcelona, Spain [2] ICFO-Institut de Ciencies Fotoniques, Castelldefels, E-08860 Barcelona, Spain.
authors: Marcus
authors: M
authors: Huber
authors: School of Physics and Astronomy, Scottish Universities Physics Alliance (SUPA), University of Glasgow, Glasgow G12 8QQ, UK.
authors: Martin P J
authors: MP
authors: Lavery
authors: School of Physics and Astronomy, Scottish Universities Physics Alliance (SUPA), University of Glasgow, Glasgow G12 8QQ, UK.
authors: Miles J
authors: MJ
authors: Padgett
authors: 1] Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Boltzmanngasse 5, Vienna A-1090, Austria [2] Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Boltzmanngasse 3, Vienna A-1090, Austria.
authors: Anton
authors: A
authors: Zeilinger