Entangled Images from Four-Wave Mixing

TL;DR: In this article, the contribution of the extreme ultraviolet (EUV) and X-ray free electron laser (FELs) on the development of original experimental strategies to study non-equilibrium behavior of matter at the femtosecond-nanometer time-length scales is discussed.

TL;DR: In this article , the authors theoretically proposed and experimentally demonstrated a scheme for generating an ULS CV deterministic entanglement containing 2×20 400 optical modes and 81 596 squeezed modes.

Abstract: A crucial aspect of quantum information is the establishment of multiuser quantum networks, ensuring secure transmission of information among separated users. However, establishing a large-scale network remains a substantial challenge, requiring massive and compact Einstein-Podolsky-Rosen (EPR) entangled states. Here, we experimentally generate a 5 by 5 continuous variable (CV) EPR entanglement array using a metalens array. Moreover, on the basis of such a compact EPR entanglement array, we establish a five-user all-optical quantum state sharing (AOQSS) network with fidelity beating the corresponding classical limit, which is currently the largest AOQSS network in the CV regime. These results provide a promising platform for the generation of massive and compact EPR entangled states and the construction of large-scale all-optical multiuser quantum networks. Our compact approach for generating CV EPR entanglement based on metasurface opens up avenues for advanced quantum networks.

TL;DR: In this article, the shape of a binary amplitude mask in the path of one of the twin beams is estimated by using the spatial quantum correlations present in twin beams to extract information about the shape.

TL;DR: This work demonstrates entanglement involving the spatial modes of the electromagnetic field carrying orbital angular momentum, which provides a practical route to entangled states that involves many orthogonal quantum states, rather than just two Multi-dimensional entangled states could be of considerable importance in the field of quantum information, enabling, for example, more efficient use of communication channels in quantum cryptography.

TL;DR: The Peres-Horodecki criterion of positivity under partial transpose is studied in the context of separability of bipartite continuous variable states and turns out to be a necessary and sufficient condition for separability.

TL;DR: An inseparability criterion based on the total variance of a pair of Einstein-Podolsky-Rosen type operators is proposed for continuous variable systems and turns out to be a necessary and sufficient condition for inseparability.

TL;DR: In this article, the orbital angular momentum of photons is exploited to achieve multi-dimensional entanglement in higher dimensions, i.e., the state of the electromagnetic field with phase singularities (doughnut modes).