We propose and characterize a quantum interface between telecommunication wavelengths (1311 nm) and an Yb-dipole transition (369.5 nm) based on a second order sum frequency process in a PPKTP waveguide. An external (internal) conversion efficiency above 5% (10%) is shown using classical bright light.
TheThe successful employment of high-dimensional quantum correlations and its integration in telecommunication infrastructures is vital in cutting-edge quantum technologies for increasing robustness and key generation rate. Position-momentum Einstein-Podolsky-Rosen (EPR) entanglement of photon pairs are a promising resource of such high-dimensional quantum correlations. Here, we experimentally certify EPR correlations of photon pairs generated by spontaneous parametric down-conversion (SPDC) in a nonlinear crystal with type-0 phase-matching at telecommunication wavelength for the first time. T…
Near-Infrared and Telecommunication-Wavelength Photon-Pair Source in Optical Fiber
University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；Illinois Quantum Information Science & Technology Center (IQUIST)（伊利诺伊量子信息与科技中心）；Cornell University（康奈尔大学）
Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian states at the telecommunication wavelength is still underdeveloped. Here, we generate highly-pure-single-photon states, one of the most primitive non-Gaussian states, by using a heralding scheme with an optical parametric oscillator and a superconducting nano-strip photon detector. The Wigner negativity, the indicator of non-classicality, of the generated sin…
Artificial atoms in solids are leading candidates for quantum networks, scalable quantum computing, and sensing, as they combine long-lived spins with mobile and robust photonic qubits. The central requirements for the spin-photon interface at the heart of these systems are long spin coherence times and efficient spin-photon coupling at telecommunication wavelengths. Artificial atoms in silicon have a unique potential to combine the long coherence times of spins in silicon with telecommunication wavelength photons in the world's most advanced microelectronics and photonics platform. However, a…
Quantum repeaters are indispensable tools for long-distance quantum communication. However, frequency matching between entangled photon sources and remote quantum memories (QMs) is difficult, which is an obstacle to the implementation of quantum repeaters. In this paper, we demonstrate a method to achieve the coupling of a Pr:YSO as a fixed-time QM with a single telecommunication-wavelength photon through frequency stabilization using an optical frequency comb over all applied laser wavelengths. The demonstrated method can lead to the implementation of a quantum repeater scheme enabling an imp…
On-demand single-photon sources emitting pure and indistinguishable photons at the telecommunication wavelength are a critical asset towards the deployment of fiber-based quantum networks. Indeed, single photons may serve as flying qubits, allowing communication of quantum information over long distances. Self-assembled InAs quantum dots embedded in GaAs constitute an excellent nearly deterministic source of high quality single photons, but the vast majority of sources operate in the 900-950 nm wavelength range, precluding their adoption in a quantum network. Here, we present a quantum frequen…
Multimode Squeezed State for Reconfigurable Quantum Networks at Telecommunication Wavelengths
ICFO - Instituto de Ciencias Fotonicas, The Barcelona Institute of Science and Technology（ICFO-光子科学研究所，巴塞罗那科学技术研究所）；Laboratoire Kastler Brossel, Sorbonne Université, ENS-Université PSL, CNRS, Collège de France（卡斯勒布罗塞尔实验室，索邦大学，巴黎文理研究大学，法国国家科学研究中心，法兰西公学院）；Sorbonne Université, LIP6, CNRS（索邦大学，LIP6实验室，法国国家科学研究中心）
Achieving high level of pulsed squeezing, in a platform which offers integration and stability, is a key requirement for continuous-variable quantum information processing. Typically highly squeezed states are achieved with narrow band optical cavities and bulk crystals, limiting scalability. Using single-pass parametric down conversion in an integrated optical device, we demonstrate quadrature squeezing of picosecond pulses in a thin-film lithium niobate strip-loaded waveguide. For on-chip peak powers of less than 0.3 W, we measure up to -0.33$\pm$0.07 dB of squeezing with an inferred on-chip…
Quantum networks will enable a variety of applications, from secure communication and precision measurements to distributed quantum computing. Storing photonic qubits and controlling their frequency, bandwidth and retrieval time are important functionalities in future optical quantum networks. Here we demonstrate these functions using an ensemble of erbium ions in yttrium orthosilicate coupled to a silicon photonic resonator and controlled via on-chip electrodes. Light in the telecommunication C-band is stored, manipulated and retrieved using a dynamic atomic frequency comb protocol controlled…
Fiber-based quantum networks require photons at telecommunications wavelengths to interconnect qubits separated by long distances. Trapped ions are leading candidates for quantum networking with high-fidelity two-qubit gates, long coherence times, and the ability to readily emit photons entangled with the ion's internal qubit states. However, trapped ions typically emit photons at wavelengths incompatible with telecommunications fiber. Here, we demonstrate frequency conversion of visible photons, emitted from the S-P dipole transition of a trapped Ba+ ion, into the telecommunications C-band. T…
Optical characterization of excited-state spin Hamiltonians and clock transitions at telecommunication wavelength in Tm3+:YAlO3
Department of Applied Physics, University of Geneva（日内瓦大学应用物理系）；PSI Center for Photon Science, Paul Scherrer Institute（保罗谢尔研究所光子科学中心）；Laboratory for Solid State Physics and Quantum Center, ETH Zurich（苏黎世联邦理工学院固体物理与量子中心）；Institute of Physics, EPF Lausanne（洛桑联邦理工学院物理研究所）
We report an optical homogeneous linewidth of 580 $\pm$ 20 Hz of Er$^{3+}$:Y$_2$O$_3$ ceramics at millikelvin temperatures, narrowest so far in rare-earth doped ceramics. We show slow spectral diffusion of $\sim$2 kHz over a millisecond time scale. Temperature, field dependence of optical coherence and spectral diffusions reveal the remaining dephasing mechanism as elastic two-level systems in polycrystalline grain boundaries and superhyperfine interactions of Er$^{3+}$ with nuclear spins. In addition, we perform spectral holeburning and measure up to 5 s hole lifetimes. These spectroscopic re…
Single-photon addition to multimode quantum fields at telecom wavelengths using lithium niobate and its doped variants
School of Quantum Technology, Defence Institute of Advanced Technology（国防先进技术研究院量子技术学院）；Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France（卡斯勒·布罗塞尔实验室，索邦大学，法国国家科学研究中心，巴黎文理研究大学，法兰西学院）
For practical quantum communications, the efficiency of the entire system (source, quantum channel and detectors) must be taken into account. In many urban environments, the quantum channel in the form of telecommunication optical fiber (confirming to ITU G.652D standards) are available, but the detectors in this range typically have low efficiency. We investigate the possibility that for campus-type communications, entangled photons prepared in the Near-Infrared Range (NIR) can be transmitted successfully while preserving polarization entanglement. We demonstrate the distribution of degenerat…
Entanglement distribution over long distances is essential for many quantum communication schemes like quantum teleportation, some variants of quantum key distribution, or implementations of a quantum internet. Distributing entanglement through standard telecommunication fiber is particularly important for quantum key distribution protocols with low vulnerability over metropolitan distances. However, entanglement distribution over long distance through optical fiber so far could only be accomplished with moderate photon pair rates. In this work, we present entanglement distribution over 50km o…
The global quantum internet will require long-lived, telecommunications band photon-matter interfaces manufactured at scale. Preliminary quantum networks based upon photon-matter interfaces which meet a subset of these demands are encouraging efforts to identify new high-performance alternatives. Silicon is an ideal host for commercial-scale solid-state quantum technologies. It is already an advanced platform within the global integrated photonics and microelectronics industries, as well as host to record-setting long-lived spin qubits. Despite the overwhelming potential of the silicon quantum…
Spectroscopy and Coherence of an Excited-State Transition in Tm$^{3+}$:YAlO$_3$ at Telecommunication Wavelength
University of Geneva（日内瓦大学）；Constructor University Bremen（不来梅构造大学）；Xanadu Quantum Technologies Inc.（仙杜量子技术有限公司）；QuTech（奎泰克）；Delft Technical University（代尔夫特理工大学）；Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University（尼古拉·哥白尼大学物理、天文学和信息学院物理研究所）；Q*Bird BV（Q*Bird有限公司）；Intel Corporation（英特尔公司）；Montana State University（蒙大拿州立大学）
Quantum networks enable a broad range of practical and fundamental applications spanning distributed quantum computing to sensing and metrology. A cornerstone of such networks is an interface between telecom photons and quantum memories. Here we demonstrate a novel approach based on cavity optomechanics that utilizes the susceptibility of spin qubits to strain. We use it to control electron spins of nitrogen-vacancy centers in diamond with photons in the 1550 nm telecommunications wavelength band. This method does not involve qubit optical transitions and is insensitive to spectral diffusion. …
Reconfigurable quantum photonic processors are an essential technology for photonic quantum computing. Although most large-scale reconfigurable quantum photonic processors were demonstrated at the telecommunications C band around 1550 nm, high-performance single photon light sources utilizing quantum dots that are well-suited for photonic quantum computing operate at a variety of wavelengths. Thus, a demand exists for the compatibility of quantum photonic processors with a larger wavelength range. Silicon nitride (SiN) has a high confinement and wide transparency window, enabling compact, low-…
Problems related to wavelength assignment (WA) in optical communications networks involve allocating transmission wavelengths for known transmission paths between nodes that minimize a certain objective function, for example, the total number of wavelengths. Playing a central role in modern telecommunications, this problem belongs to NP-complete class for a general case, so that obtaining optimal solutions for industry relevant cases is exponentially hard. In this work, we propose and develop a quantum-inspired algorithm for solving the wavelength assignment problem. We propose an advanced emb…
Quantum networks have been shown to connect users with full-mesh topologies without trusted nodes. We present advancements on our scalable polarisation entanglement-based quantum network testbed, which has the ability to perform protocols beyond simple quantum key distribution. Our approach utilises wavelength multiplexing, which is ideal for quantum networks across local metropolitan areas due to the ease of connecting additional users to the network without increasing the resource requirements per user. We show a 10 user fully connected quantum network with metropolitan scale deployed fibre …
