The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,f...The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,femtosecond laser-written integrated photonic circuits,which have already been assessed for use in quantum information experiments in the 800-nm wavelength range,have great potential.In fact,these circuits,being written in glass,can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers,which is a key requirement for a low-loss processing node in future quantum optical networks.In addition,for several applications,quantum photonic devices must be dynamically reconfigurable.Here,we experimentally demonstrate the high performance of femtosecond laser-written photonic circuits for use in quantum experiments in the telecom band,and we demonstrate the use of thermal shifters,which were also fabricated using the same femtosecond laser,to accurately tune such circuits.State-of-the-art manipulation of single-and two-photon states is demonstrated,with fringe visibilities greater than 95%.The results of this work open the way to the realization of reconfigurable quantum photonic circuits based on this technological platform.展开更多
Encoding many qubits in different degrees of freedom(DOFs)of single photons is one of the routes toward enlarging the Hilbert space spanned by a photonic quantum state.Hyperentangled photon states(that is,states showi...Encoding many qubits in different degrees of freedom(DOFs)of single photons is one of the routes toward enlarging the Hilbert space spanned by a photonic quantum state.Hyperentangled photon states(that is,states showing entanglement in multiple DOFs)have demonstrated significant implications for both fundamental physics tests and quantum communication and computation.Increasing the number of qubits of photonic experiments requires miniaturization and integration of the basic elements,and functions to guarantee the setup stability,which motivates the development of technologies allowing the precise control of different photonic DOFs on a chip.We demonstrate the contextual use of path and polarization qubits propagating within an integrated quantum circuit.We tested the properties of four-qubit linear cluster states built on both DOFs,and we exploited them to perform the Grover's search algorithm according to the one-way quantum computation model.Our results pave the way toward the full integration on a chip of hybrid multi-qubit multiphoton states.展开更多
基金This work was supported by the ERC-Starting Grant 3D-QUEST(3DQuantum Integrated Optical Simulationgrant agreement no.307783,http://www.3dquest.eu)by the Marie Curie Initial Training Network PICQUE(Photonic Integrated Compound Quantum Encoding,grant agreement no.608062,funding Program:FP7-PEOPLE-2013-ITN,http://www.picque.eu).
文摘The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,femtosecond laser-written integrated photonic circuits,which have already been assessed for use in quantum information experiments in the 800-nm wavelength range,have great potential.In fact,these circuits,being written in glass,can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers,which is a key requirement for a low-loss processing node in future quantum optical networks.In addition,for several applications,quantum photonic devices must be dynamically reconfigurable.Here,we experimentally demonstrate the high performance of femtosecond laser-written photonic circuits for use in quantum experiments in the telecom band,and we demonstrate the use of thermal shifters,which were also fabricated using the same femtosecond laser,to accurately tune such circuits.State-of-the-art manipulation of single-and two-photon states is demonstrated,with fringe visibilities greater than 95%.The results of this work open the way to the realization of reconfigurable quantum photonic circuits based on this technological platform.
基金supported by the European Union through the project FP7-ICT-2011-9-600838(QWAD Quantum Waveguides Application and Developmentwww.qwad-project.eu)by FIRB,Futuro in Ricerca HYTEQ.
文摘Encoding many qubits in different degrees of freedom(DOFs)of single photons is one of the routes toward enlarging the Hilbert space spanned by a photonic quantum state.Hyperentangled photon states(that is,states showing entanglement in multiple DOFs)have demonstrated significant implications for both fundamental physics tests and quantum communication and computation.Increasing the number of qubits of photonic experiments requires miniaturization and integration of the basic elements,and functions to guarantee the setup stability,which motivates the development of technologies allowing the precise control of different photonic DOFs on a chip.We demonstrate the contextual use of path and polarization qubits propagating within an integrated quantum circuit.We tested the properties of four-qubit linear cluster states built on both DOFs,and we exploited them to perform the Grover's search algorithm according to the one-way quantum computation model.Our results pave the way toward the full integration on a chip of hybrid multi-qubit multiphoton states.
