Related papers: Time-dependent switching of the photon entanglemen…

We present the novel embodiment of a photonic qubit that makes use of one continuous spatial degree of freedom of a single photon and relies on the the parity of the photon's transverse spatial distribution. Using optical spontaneous…

Scalable quantum systems require deterministic entangled photon pair sources. Here, we demonstrate a scheme that uses a dipole-coupled defect pair to deterministically emit polarization-entangled photon pairs. Based on this scheme, we…

Quantum states of light are central resources for quantum communication, networking, and photonic information processing. In many quantum emitters, coherent internal dynamics arising from intrinsic or field-induced level splittings imprint…

Entanglement is a unique quantum mechanical attribute and a fundamental resource of quantum technologies. Entanglement can be achieved in various individual degrees of freedom, nonetheless some systems are able to create simultaneous…

We present a protocol for performing entanglement swapping with intense pulsed beams. In a first step, the generation of amplitude correlations between two systems that have never interacted directly is demonstrated. This is verified in…

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 study theoretically the entanglement of two-photon states in the ground state of the intersubband cavity system, the so-called polariton vacuum. The system consists of a sequence of doped quantum wells located inside a microcavity and…

We show here that the photonic states emitted by ensembles of multilevel atoms via a superradiance process exhibit entanglement in the modal (frequency) degree of freedom, making this collective emission process a favorable candidate for a…

Engineering atom-atom interactions is essential both for controlling novel phases of matter and for efficient preparation of many-body entangled states, which are key resources in quantum communication, computation, and metrology. In this…

We theoretically investigate polarization-entangled photon generation by using a semiconductor quantum dot embedded in a microcavity. The entangled states can be produced by the application of two cross-circularly polarized laser fields.…

We present a setup for quantum cryptography based on photon pairs in energy-time Bell states and show its feasability in a laboratory experiment. Our scheme combines the advantages of using photon pairs instead of faint laser pulses and the…

We address the problem of the persistence of entanglement of quantum light under mode transformations, where orthogonal modes define the parties between which quantum correlations can occur. Since the representation of a fixed photonic…

A silicon quantum photonic circuit was proposed and demonstrated as an integrated quantum light source for telecom band polarization entangled Bell state generation and dynamical manipulation. Biphoton states were firstly generated in four…

Multi-photon entanglement plays a central role in optical quantum technologies. One way to entangle two photons is to prepare them in orthogonal internal states, for example, in two polarisations, and then send them through a balanced beam…

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…

Invariant entangled states remain unchanged under simultaneous identical unitary transformations of all their subsystems. We experimentally generate and characterize such invariant two-, four-, and six-photon polarization entangled states.…

We report a practical non-postselection entanglement concentration scheme in which a maximally entangled Bell-state photon pair is produced from two pairs of partially (or non-maximally) entangled photons. Since this scheme is built only…

The control and manipulation of quantum-entangled non-local states is a crucial step for the development of quantum information processing. A promising route to achieve such states on a wide scale is to couple solid-state quantum emitters…

The pairwise entanglement of an arbitrary atomic pair randomly extracted from a laser-driven dense multiqubit sample in the presence of quantum dissipation due to spontaneous emission is considered. The dipole-dipole interaction between the…

Current photon entangling schemes require resources that grow with the photon number. We present a new approach that generates quantum entanglement between many photons, using only a single source of entangled photon pairs. The different…