相关论文: Four Photon Entanglement from Down Conversion

The state of the signal-idler photon pair of spontaneous parametric down conversion(SPDC) is a typical nonlocal entangled pure state with zero entropy. The precise correlation of the subsystems is completely described by the state. However,…

Entangled photons are crucial for quantum technologies, but generating arbitrary entangled photon states deterministically, efficiently, and with high fidelity remains a challenge. Here, we demonstrate how hybridization and dipole-dipole…

High-quality entangled photon pairs generated via spontaneous parametric down-conversion have made great contributions to the modern quantum information science and the fundamental tests of quantum mechanics. However, the quality of the…

In this work the degree of entanglement of two-photon states generated by parametric-down conversion with a phase mismatch is computed in terms of the temperature of the nonlinear medium where the interaction takes place. The minimum…

We calculate the bi-photon state generated by spontaneous parametric down conversion in a thin crystal and under collinear phase matching conditions using a pump consisting of any superposition of Laguerre-Gauss modes. The result has no…

When multiple quantum emitters radiate, their emission rate may be enhanced or suppressed due to collective interference in a process known as super- or subradiance. Such processes are well-known to occur also in light emission by free…

We consider novel method for implementation of hybrid entanglement between microscopic and macroscopic states on output of spontaneous parametric down converter through the depletion of the pump wave. The generated signal, idler and pumping…

We show that the quantum interference between downconverted photon pairs and photons from coherent laser light can produce a maximally path entangled N-photon output component with a fidelity greater than 90% for arbitrarily high photon…

A formalism for two-photon Stokes parameters is introduced to describe the polarization entanglement of photon pairs. This leads to the definition of a degree of two-photon polarization, which describes the extent to which the two photons…

Conventional polarimetry, including schemes leveraging entangled light, characterizes optical samples through linear transformations of polarization states. We introduce a two-photon probing approach in which both photons of an entangled…

Decay of a four-level diamond scheme via a cascade is a potential source of entangled photon pairs. A solid-state implementation is the biexciton cascade in a semiconductor quantum dot. While high entanglement fidelities have been…

We propose an experimentally feasible scheme for generating a two $2\times4\times4$ dimensional photons hyperentangled state, entangled in polarization, frequency and spatial mode. This scheme is mainly based on a parametric down-conversion…

The phenomenon of entanglement is the basis of quantum information and quantum communication processes. Entangled systems with a large number of photons are of great interest at present because they provide a platform for streaming…

We will study entangled two-photon states generated from a two-mode supersymmetric model and quantify degree of entanglement in terms of the entropy of entanglement. The influences of the nonlinearity on the degree of entanglement is also…

The maximum entanglement between two coupled qubits in the steady state under two independent incoherent sources of excitation is reported. Asymmetric configurations where one qubit is excited while the other one dissipates the excitation…

Using a spontaneous parametric-downconversion source of photon pairs, we are working towards the creation of arbitrary 2-qubit quantum states with high fidelity. Currently, all physically allowable combinations of polarization entanglement…

We obtain a four-photon polarization-entangled state with a visibility as high as (95.35\pm 0.45)% directly from a single down-conversion source. A success probability of (81.54\pm 1.38)% is observed by applying this entangled state to…

We report experimental results on mixed-state generation by multiple scattering of polarization-entangled photon pairs created from parametric down-conversion. By using a large variety of scattering optical systems we have experimentally…

Integrated entangled photon pair source is an essential resource for both fundamental investigations and practical applications of quantum information science. Currently there have been several types of entanglement, among which the…

Hyperentangled photonic states - exhibiting nonclassical correlations in several degrees of freedom - offer improved performance of quantum optical communication and computation schemes. Experimentally, a hyperentanglement of…