Related papers: Efficient polarisation-preserving frequency conver…
High-speed long-range quantum communication requires combining frequency multiplexed photonic channels with quantum memories. We experimentally demonstrate an integrated quantum frequency conversion protocol that can convert between…
Quantum frequency conversion (QFC) is essential for bridging the spectral gap between stationary qubits and low-loss optical communication channels. In this work, we demonstrate a short-wavelength-pumping QFC with the first-order…
We report on the transmission of telecom photons entangled with a multimode solid-state quantum memory over a deployed optical fiber in a metropolitan area. Photon pairs were generated through spontaneous parametric down-conversion, with…
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…
Entanglement between stationary quantum memories and photonic channels is the essential resource for future quantum networks. Together with entanglement distillation it will enable for efficient distribution of quantum states. Here we…
Quantum frequency conversion (QFC), a nonlinear optical process in which the frequency of a quantum light field is altered while conserving its non-classical correlations, was first demonstrated 20 years ago. Meanwhile, it is considered an…
We report on the implementation of quantum entanglement distribution and quantum state teleportation over a 14.4-km urban dark-fiber link, which is partially underground, partially overhead, and patched in several stations. We characterize…
We report the demonstration of a bulk, intrinsically phase-stable source of polarization- and time-energy-entangled photon pairs at 810nm and 1550nm, directly coupled into single-mode optical fibers. This highly non-degenerate wavelength…
A practical way to link separate nodes in quantum networks is to send photons over the standard telecom fibre network. This requires sub-Poissonian photon sources in the telecom wavelength band around 1550 nm, where the photon coherence…
Quantum networks consisting of quantum memories and photonic interconnects can be used for entanglement distribution (L.-M.Duan and H. J. Kimble, PRL 90, 253601 (2003), H. J. Kimble, Nat. 453, 1023 EP (2008)), quantum teleportation…
A quantum repeater node is presented based on trapped ions that act as single photon emitters, quantum memories and an elementary quantum processor. The node's ability to establish entanglement across two 25 km-long optical fibers…
We entangle each individual matter-qubit in a register of ten to a separate travelling photon. The qubits are encoded in a string of cotrapped atomic ions. By switching the trap confinement, ions are brought one at a time into the waist of…
Integration is currently the only feasible route towards scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical…
Fiber-based distribution of triggered, entangled, single-photon pairs is a key requirement for the future development of terrestrial quantum networks. In this context, semiconductor quantum dots (QDs) are promising candidates for…
Filtering is commonly used in quantum optics to reject noise photons, and also to enable interference between independent photons. However, filtering the joint spectrum of photon pairs can reduce the inherent coincidence probability or…
We demonstrate entanglement between the polarization of an infrared photon and a metastable $^{88}$Sr$^+$ ion qubit. This entanglement persists after transmitting the photon over a $2.8\:$km long commercial fiber deployed in an urban…
We report an experiment demonstrating quantum frequency conversion of weak light pulses compatible with atomic quantum memories to telecommunication wavelengths. We use a PPLN nonlinear waveguide to convert weak coherent states at the…
We report a detailed study of the noise properties of a visible-to-telecom photon frequency converter based on difference frequency generation (DFG). The device converts 580 nm photons to 1541 nm using a strong pump laser at 930 nm, in a…
In large-area quantum networks based on optical fibers, photons are the fundamental carriers of information as so-called flying qubits. They may also serve as the interconnect between different components of a hybrid architecture, which…
Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an…