Related papers: Heralded amplification for precision measurements …
Slow light based on the effect of electromagnetically induced transparency is of great interest due to its applications in low-light-level nonlinear optics and quantum information manipulation. The previous experiments all dealt with the…
Efficient and bright single photon sources on photonic chips are key to scaling quantum technologies. Spontaneous four wave mixing in micro-ring resonators creates excellent narrowband and tunable photon sources. We experimentally…
We propose a scheme to generate two-photon, two-atom, or atom-photon entangledstates with a coupled system of two cavities. In our scheme, two cavity photonsare exchanged by the direct inter-cavity coupling, while atoms in the…
Methods which aim at universal applicability must be able to describe both weak and strong electronic correlation with equal facility. Such methods are in short supply. The combination of symmetry projection for strong correlation and…
We report significant improvements in the retrieval efficiency of a single excitation stored in an atomic ensemble and in the subsequent generation of strongly correlated pairs of photons. A 50% probability to transform the stored…
In the last few years there has been a lot of interest in quantum repeater protocols using only atomic ensembles and linear optics. Here we show that the local generation of high-fidelity entangled pairs of atomic excitations, in…
A theoretical spin-based scheme for performing a variety of quantum computations is presented. It makes use of an array of multiple identical computer vectors of phosphorus-doped silicon where the nuclei serve as logical qubits and the…
Quantum memories for light are essential components in quantum technologies like long-distance quantum communication and distributed quantum computing. Recent studies have shown that long optical and spin coherence lifetimes can be observed…
We describe a measurement-based state preparation scheme for the efficient build up of cluster states in atom-cavity systems. As in a recent proposal for the generation of maximally entangled atom pairs [Metz et al., Phys. Rev. Lett. 97,…
We put forward an effective amplification protocol for protecting the single-photon multi-mode W state of the time-bin qubit. The protocol only relies on linear optical elements, such as the $50:50$ beam splitters, variable beam splitters…
We propose a state preparation protocol based on sequential measurements of a central spin coupled with a spin ensemble, and investigate the usefulness of the generated multi-spin states for quantum enhanced metrology. Our protocol is shown…
We report on a source of heralded narrowband (3MHz) single photons compatible with solid-state spin-wave quantum memories based on praseodymium doped crystals. Widely non-degenerate narrow-band photon pairs are generated using cavity…
In the present paper we consider a quantum memory scheme for light diffusely propagating through a spatially disordered atomic gas. The diffuse trapping of the signal light pulse can be naturally integrated with the mechanism of stimulated…
Collective spins of large atomic samples trapped inside optical resonators can carry quantum information that can be processed in a way similar to quantum computation with continuous variables. It is shown here that by combining the…
We show experimentally that a broad class of interactions involving quantum harmonic oscillators can be made stronger (amplified) using a unitary squeezing protocol. While our demonstration uses the motional and spin states of a single…
Probing the collective spin state of an ensemble of atoms may provide a means to reduce heating via the photon recoil associated with the measurement and provide a robust, scalable route for preparing highly entangled states with…
Samples with few hundred atoms within a few micrometer sized region of space are large enough to provide efficient cooperative absorption and emission of light, and small enough to ensure strong dipole-dipole interactions when atoms are…
An approximate relativistic two-component Hamiltonian for use in molecular electronic structure calculations is derived in the form of a sum of fixed atom-centered kinetic and spin-orbit operators added to the non-relativistic Hamiltonian.…
Quantum entanglement emerges naturally in interacting quantum systems and plays a central role in quantum information processing. Remarkably, it is possible to generate entanglement even in the absence of direct interactions: provided that…
We propose an ensemble algorithm, which provides a new approach for evaluating and summing up a set of function samples. The proposed algorithm is not a quantum algorithm, insofar it does not involve quantum entanglement. The query…