Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Generation and manipulation of entangled photon states by a universal source of entanglement

Marco Barbieri, F. De Martini, G. Di Nepi, Paolo Mataloni

Published Oct 21, 2004• 0 citations
Publisher

Abstract

Maximally entangled states, Werner state and maximally entangled mixed states (MEMS) have been created and fully characterized by a novel high brilliance universal source of entangled photon pairs with striking spatial characteristics. Mixed states of any structure, spanning a 2 x 2 Hilbert space may be created by this source. The non local properties of the generated entanglement have been tested by standard Bell measurements. Tunable Werner states and Maximally Entangled Mixed States (MEMS) have been created by an original patchwork technique and investigated by quantum tomography. The entropic and nonlocal properties of these states have been also undertaken.

DOI
10.1117/12.582787

Related papers

Parametric source of two-photon states with a tunable degree of entanglement and mixing: Experimental preparation of Werner states and maximally entangled mixed states

C. Cinelli, G. Di Nepi, F. De Martini +2 more

A parametric source of polarization-entangled photon pairs with striking spatial characteristics is reported. The distribution of the output electromagnetic $\mathbf{k}$ modes excited by spontaneous parametric down-conversion and coupled to the output detectors can be very broad. Using these states realized over a full entanglement ring output distribution, the nonlocal properties of the generated entanglement have been tested by standard Bell measurements and by Ou-Mandel interferometry. A ``mode-patchwork'' technique based on the quantum superposition principle is adopted to synthesize in a straightforward and reliable way any kind of mixed state, of large conceptual and technological interest in modern quantum information. Tunable Werner states and maximally entangled mixed states have indeed been created by this technique and investigated by quantum tomography. A study of the entropic and nonlocal properties of these states has been undertaken experimentally and theoretically, by a unifying variational approach.

Physical Review A•Aug 27, 2004•67 citations

Generation and Characterization of Werner States and Maximally Entangled Mixed States by a Universal Source of Entanglement

Marco Barbieri, F. De Martini, G. Di Nepi +1 more

We 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.

Physical Review Letters•Apr 28, 2004•121 citations

Violation of Bell inequalities and Quantum Tomography with Pure-states, Werner-states and Maximally Entangled Mixed States created by a Universal Quantum Entangler

Marco Barbieri, F. De Martini, G. Di Nepi +1 more

Entangled pure-states, Werner-states and generalized mixed-states of any structure, spanning a 2x2 Hilbert space are created by a novel high-brilliance universal source of polarization-entangled photon pairs. The violation of a Bell inequality has been tested for the first time with a pure-state, indeed a conceptually relevant ideal condition, and with Werner-states. The generalized ''maximally entangled mixed states'' (MEMS) were also synthetized for the first time and their exotic properties investigated by means of a quantum tomographic technique.

arXiv:quant-ph/0303018•Mar 4, 2003•3 citations

Generation of (2 × 2) and (4 × 4) two‐photon states with tunable degree of entanglement and mixedness

Marco Barbieri, C. Cinelli, F. De Martini +1 more

Abstract A parametric source of polarization entangled photon pairs with peculiar spatial characteristics allows to generate any kind of bi‐partite entangled states with tunable dgree of entanglement and mixedness. In particular, maximally entangled mixed states (MEMS) have been created in a reliable way by a “patchwork” technique and investigated by quantum tomography. By the same source, momentum‐polarization hyper‐entangled two‐photon states have been synthesized. The quality of the entanglement in the two degrees of freedom has been tested by multimode Hong‐Ou‐Mandel interferometry.

Fortschritte der Physik•Oct 11, 2004•9 citations

Generation and Applications of Single Photon States and Entangled Photon States

Marco Barbieri

Two quantum interferometry processes with possible significant applications in quantum information technology are presented. A two frequency Mach‐Zehnder interferometer realizes the nonlinear frequency conversion of a single photon qubit. The information‐preserving character of the nonlinear process allows to transfer the coherence of the input to the output state. Furthermore, we describe a novel high brilliance universal source of entangled photon pairs with peculiar spatial characteristics, which allows to generate two particle entangled states, either pure or mixed of any structure. By this source we have synthesized and fully characterized by quantum tomography Werner states and maximally entangled mixed states (MEMS). The non local properties of these states have been tested by Bell measurements.

AIP conference proceedings•Jan 1, 2004•0 citations

Detection of Entanglement with Polarized Photons: Experimental Realization of an Entanglement Witness

Marco Barbieri, F. De Martini, G. Di Nepi +3 more

We report on the first experimental realization of an entanglement witness, a method to detect entanglement with few local measurements. The present demonstration has been performed with polarized photons in Werner states, a well-known family of mixed states that can be either separable or nonseparable. The Werner states are generated by a novel high brilliance source of bipartite entangled states by which the state mixedness can be easily adjusted.

arXiv:quant-ph/0307003•Physical Review Letters•Nov 24, 2003•192 citations
Maximally entangled states, Werner state and maximally entangled mixed states (MEMS) have been created and fully characterized by a novel high brilliance universal source of entangled photon pairs with striking spatial characteristics. Mixed states of any structure, spanning a 2 x 2 Hilbert space may be created by this source. The non local properties of the generated entanglement have been tested by standard Bell measurements. Tunable Werner states and Maximally Entangled Mixed States (MEMS) have been created by an original patchwork technique and investigated by quantum tomography. The entropic and nonlocal properties of these states have been also undertaken.
A parametric source of polarization-entangled photon pairs with striking spatial characteristics is reported. The distribution of the output electromagnetic k\mathbf{k}k modes excited by spontaneous parametric down-conversion and coupled to the output detectors can be very broad. Using these states realized over a full entanglement ring output distribution, the nonlocal properties of the generated entanglement have been tested by standard Bell measurements and by Ou-Mandel interferometry. A ``mode-patchwork'' technique based on the quantum superposition principle is adopted to synthesize in a straightforward and reliable way any kind of mixed state, of large conceptual and technological interest in modern quantum information. Tunable Werner states and maximally entangled mixed states have indeed been created by this technique and investigated by quantum tomography. A study of the entropic and nonlocal properties of these states has been undertaken experimentally and theoretically, by a unifying variational approach.
Entangled pure-states, Werner-states and generalized mixed-states of any structure, spanning a 2x2 Hilbert space are created by a novel high-brilliance universal source of polarization-entangled photon pairs. The violation of a Bell inequality has been tested for the first time with a pure-state, indeed a conceptually relevant ideal condition, and with Werner-states. The generalized ''maximally entangled mixed states'' (MEMS) were also synthetized for the first time and their exotic properties investigated by means of a quantum tomographic technique.
Abstract A parametric source of polarization entangled photon pairs with peculiar spatial characteristics allows to generate any kind of bi‐partite entangled states with tunable dgree of entanglement and mixedness. In particular, maximally entangled mixed states (MEMS) have been created in a reliable way by a “patchwork” technique and investigated by quantum tomography. By the same source, momentum‐polarization hyper‐entangled two‐photon states have been synthesized. The quality of the entanglement in the two degrees of freedom has been tested by multimode Hong‐Ou‐Mandel interferometry.
Two quantum interferometry processes with possible significant applications in quantum information technology are presented. A two frequency Mach‐Zehnder interferometer realizes the nonlinear frequency conversion of a single photon qubit. The information‐preserving character of the nonlinear process allows to transfer the coherence of the input to the output state. Furthermore, we describe a novel high brilliance universal source of entangled photon pairs with peculiar spatial characteristics, which allows to generate two particle entangled states, either pure or mixed of any structure. By this source we have synthesized and fully characterized by quantum tomography Werner states and maximally entangled mixed states (MEMS). The non local properties of these states have been tested by Bell measurements.