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

Journal Article · Sun Aug 01 04:00:00 EDT 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.70.022321· OSTI ID:20645866

Cinelli, C; Di Nepi, G; De Martini, F; Barbieri, M; Mataloni, P ^[1]

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1. Dipartimento di Fisica and Istituto Nazionale per la Fisica della Materia, Universita di Roma 'La Sapienza', Rome 00185 (Italy)

A parametric source of polarization-entangled photon pairs with striking spatial characteristics is reported. The distribution of the output electromagnetic 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.

• OSTI ID: 20645866
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 70; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BELL THEOREM
CONVERSION
CORRELATIONS
DISTRIBUTION
ENERGY LEVELS
INFORMATION THEORY
INTERFEROMETRY
MIXED STATE
MIXING
MULTI-PHOTON PROCESSES
OPTICS
PHOTONS
POLARIZATION
QUANTUM MECHANICS
TOMOGRAPHY
VARIATIONAL METHODS