Related papers: Producing the entangled photon pairs without type …
We propose a linear optical scheme that can conditionally generate high NOON states using polarization modes. This scheme provides advantages over the previous proposals on path-entangled NOON states in view of success probability or…
We describe a scheme that allows for the generation of any desired N-photon state on demand. Under ideal conditions, this requires only N single photon sources, laser pulses and linear optics elements. First, the sources should be…
We propose a simple scheme for expanding a polarization-entangled W state. By mixing a single photon and one of the photons in an n-photon W state at a polarization-dependent beam splitter (PDBS), we can obtain an (n+1)-photon W state after…
Photon subtraction is useful to produce nonclassical states of light addressed to applications in photonic quantum technologies. After a very accelerated development, this technique makes possible obtaining either single photons or optical…
Transferring entangled states between photon pairs is essential for quantum communication technologies. Semiconductor quantum dots are the most promising candidate for generating polarization-entangled photons deterministically. Recent…
Non-linear photonic crystals can be used to provide phase-matching for frequency conversion in optically isotropic materials. The phase-matching mechanism proposed here is a combination of form birefringence and phase velocity dispersion in…
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…
With the assistance of weak cross-Kerr nonlinearities, we introduce an optical scheme to fuse two small-size polarization entangled W states into a large-scale W state without qubit loss, i.e.,$\mathrm{W}_{n+m}$ state can be generated from…
We propose a scheme for entangling two field modes in two high-Q optical cavities. Making use of a virtual two-photon process, our scheme achieves maximally entangled states without any real transitions of atomic internal states, hence it…
Entangled photon states are a fundamental resource for optical quantum technologies and investigating the fundamental predictions of quantum mechanics. Up to now such states are mainly generated in macroscopic nonlinear optical systems with…
Entangled photon pairs play a major role in various modern technologies such as quantum imaging, communication, and computing. Conventional photon-pair sources are often based on spontaneous parametric down-conversion in bulk nonlinear…
We report on a simple but highly efficient source of polarization-entangled photon pairs at non-degenerate wavelengths. The fully collinear configuration of the source enables very high coupling efficiency into a single optical mode and…
The reliable distribution of high-dimensional entangled quantum states, an important resource in quantum technologies, through optical fibre networks is challenging due to the need to maintain coherence across multiple modes. Here we…
Two-photon processes are crucial in applications like microscopy and microfabrication, but their low cross-section requires intense illumination and limits, e.g., the penetration depth in nonlinear microscopy. Entangled states have been…
Using a rigorous quantum model a comprehensive study of physical properties of entangled photon pairs generated in spontaneous parametric down-conversion in chirped periodically-poled crystals is presented. Spectral, temporal, as well as…
Spin-photon interfaces are strong candidates for building blocks of future quantum networks and quantum computers. Several systems currently under examination present promising features, but none of them yet fulfil all requirements for…
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…
Unwanted multiphoton emission commonly reduces the degree of entanglement of photons generated by non-classical light sources and, in turn, hampers their exploitation in quantum information science and technology. Quantum emitters have the…
Entangled two-photon spectroscopy is expected to provide advantages compared with classical protocols. It is achieved by coherently controlling the spectral properties of energy-entangled photons. We present here an experimental setup that…
Photon-pair correlations in spontaneous parametric down conversion are ubiquitous in quantum photonics. The ability to engineer their properties for optimising a specific task is essential, but often challenging in practice. We demonstrate…