1,721,029 research outputs found
Experimental signature of quantum Darwinism in photonic cluster states
Full text linkWe report on an experimental assessment of the emergence of Quantum Darwinism (QD) from engineered open-system dynamics. We use a photonic hyperentangled source of graph states to address the effects that correlations among the elements of a multiparty environment have on the establishment of objective reality ensuing the quantum-to-classical transition. Besides embodying one of the first experimental efforts toward the characterization of QD, our work illustrates the nontrivial consequences that multipartite entanglement and, in turn, the possibility of having environment-to-system back-action have on the features of the QD framework
Experimental Quantum Darwinism simulator using photonic cluster states
No full textWe investigate the emergence of Quantum Darwinism in a photonic cluster as simulator of interactions between a quantum system and its environment. We demonstrate experimentally the effect of correlations in the emergence of objective reality
Generation and Applications of n-Qubit Hyperentangled Photon States
No full textIn recent years, a number of theoretical and experimental demonstrations regarding the use of photonic entangled states based on many qubits, spanning a large size Hilbert space has been provided. The entanglement of two particles in more than one degree of freedom, namely hyperentanglement, is a useful technique which allows to take full advantage of the possibilities offered by quantum mechanics. Compared to multiphoton entangled states, hyperentangled states offer important advantages as far as purity and generation/detection rate are concerned. The present work is intended to survey the most relevant examples of hyperentangled multiqubit photon states aimed at the verification of fundamental tests of quantum mechanics and the realization of important quantum information protocols
Generation and characterization of Werner states and maximally entangled mixed states by a universal source of entanglement
No full textWe present a novel technique for generating two-photon polarization mixed states of any structure, which is based on the peculiar spatial characteristics of a high brilliance source of entangled pairs. Werner states and maximally entangled mixed states, two well-known families of mixed states important for quantum information, have been created and fully characterized by this technique. We have also investigated and tested the nonlocal properties of these states
Optimal verification of entanglement in a photonic cluster state experiment
No full textWe report on the quantification of entanglement by means of entanglement measures on a four- and a six-qubit cluster state realized by using photons entangled both in polarization and linear momentum. This paper also addresses the question of the scaling of entanglement bounds from incomplete tomographic information on the density matrix under realistic experimental conditions
Experimental multi-state quantum discrimination through optical networks
Full text linkDeveloping strategies to effectively discriminate between different quantum states is a fundamental issue in quantum information and communication. The actual realization of generally optimal protocols in this task is often limited by the need of supplemental resources and very complex receivers. We have experimentally implemented two discrimination schemes in a minimum-error scenario based on a receiver featured by a network structure and a dynamical processing of information. The first protocol implemented in our experiment, directly inspired to a recent theoretical proposal, achieves binary optimal discrimination, while the second one provides a novel approach to multi-state quantum discrimination, relying on the dynamical features of the network-like receiver. This strategy exploits the arrival time degree of freedom as an encoding variable, achieving optimal results, without the need for supplemental systems or devices. Our results further reveal the potential of dynamical approaches to quantum state discrimination tasks, providing a possible starting point for efficient alternatives to current experimental strategies
Nonlinear Optical Excitation and k-Space Spectroscopy of Surface Polaritons in Gallium Phosphide
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
