title: Characterization of two-photon polarization mixed states generated from entangled-classical hybrid photon source.
abstract: We experimentally prepare bi-photon mixed states in polarization employing an entangled-classical hybrid photon emitter which can properly model solid-state entangled photon sources with uncorrelated background photons. Polarization-uncorrelated photon pairs in totally mixed (TM) states are embodied with classical thermal radiation, while the polarization-entangled ones in a Bell state are generated by conventional parametric down conversion. The bi-photon states generated from the hybrid photon emitter are characterized in terms of a linear entropy-tangle plane, which reveals the formation of two-qubit Werner states. We also propose a direct way for evaluating the Werner states by means of minimal coincidence counts measurements. This simple method can be widely applicable in examining the bi-photon states from solid-state entangled photon sources, in which the polarization-entangled photon pairs have temporal correlation while the background photons in the TM states do not.
authors.affiliation: Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan. kumano@es.hokudai.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Kumano
authors.forename: K
authors.initials: K
authors.lastname: Matsuda
authors.forename: S
authors.initials: S
authors.lastname: Ekuni
authors.forename: H
authors.initials: H
authors.lastname: Sasakura
authors.forename: I
authors.initials: I
authors.lastname: Suemune