Related papers: Entanglement generation via phase-matched processe…
A system of cascaded qubits interacting via the oneway exchange of photons is studied. While for general operating conditions the system evolves to a superposition of Bell states (a dark state) in the long-time limit, under a particular…
We report a simple scheme for direct generation of frequency-bin entangled photon pairs via spontaneous parametric downconversion. Our fabricated nonlinear optical crystal with two different poling periods can simultaneously satisfy two…
We report a novel Bell state preparation experiment. High-purity Bell states are prepared by using femtosecond pulse pumped \emph{nondegenerate} collinear spontaneous parametric down-conversion. The use of femtosecond pump pulse {\em does…
We demonstrate the generation of polarization-entangled photon pairs at room temperature and telecom wavelength in a AlGaAs semiconductor waveguide. The source is based on spontaneous parametric down conversion with a counterpropagating…
Bell states form a complete set of four maximally polarization entangled two-qubit quantum state. Being a key ingredient of many quantum applications such as entanglement based quantum key distribution protocols, superdense coding, quantum…
Entanglement is the basic building block of linear optical quantum computation, and as such understanding how to generate it in detail is of great importance for optical architectures. We prove that Bell states cannot be generated using…
We show a mechanism that projects a pair of neutral two-level atoms from an initially uncorrelated state to a maximally entangled state while they remain spacelike separated. The atoms begin both excited in a common electromagnetic vacuum,…
We demonstrate experimental generation of spatially-entangled photon-pairs by spontaneous parametric down conversion (SPDC) using a partial spatially coherent pump beam. By varying the spatial coherence of the pump, we show its influence on…
We present a hybrid continuous variable-discrete variable entanglement generation protocol using linear optics and homodyne measurements, capable of producing multiple high-fidelity Bell pairs per protocol iteration, with an approximate…
Entanglement is the quintessential quantum mechanical phenomenon understood to lie at the heart of future quantum technologies and the subject of fundamental scientific investigations. Mixture, resulting from noise, is often an unwanted…
The generation of entanglement across different nodes in distributed quantum architectures plays a pivotal role for different applications. In particular, deterministic, robust, and fast protocols that prepare genuine multipartite entangled…
We demonstrate a general method of engineering the joint quantum state of photon pairs produced in spontaneous parametric downconversion (PDC). The method makes use of a superlattice structure of nonlinear and linear materials, in…
We report a novel and simple approach for generating near-perfect quality polarization entanglement in a fully guided-wave fashion. Both deterministic pair separation into two adjacent telecommunication channels and the paired photons'…
By making use of the spatial shape of paired photons, parametric down-conversion allows the generation of two-photon entanglement in a multidimensional Hilbert space. How much entanglement can be generated in this way? In principle, the…
An example is given of an interaction that produces an infinite amount of entanglement in an infinitely short time, but only a finite amount in longer times. The interaction arises from a standard Kerr nonlinearity and a 50/50 beamsplitter,…
Quantum entanglement -- correlations of particles that are stronger than any classical analogue -- is the basis for research on the foundations of quantum mechanics and for practical applications such as quantum networks. Traditionally,…
We consider properties of states of many qubits, which arise after sending certain entangled states via various noisy channels (white noise, coloured noise, local depolarization, dephasing and amplitude damping). Entanglement of these…
The unconditional entanglement swapping for continuous variables is experimentally demonstrated. Two initial entangled states are produced from two nondegenerate optical parametric amplifiers operating at deamplification. Through…
We propose a scheme able to generate on demand a steady-state entanglement between two non-degenerate cavity modes. The scheme relies on the interaction of the cavity modes with driven two or three-level atoms which act as a coupler to…
We analyze theoretically spontaneous parametric down-conversion in a multimode nonlinear waveguide as a source of entangled pairs of spatial qubits, realized as superpositions of a photon in two orthogonal transverse modes of the waveguide.…