title: Polarization entanglement purification using spatial entanglement.
abstract: We present a scheme for entanglement purification with linear optics that works for currently available parametric down-conversion sources, in contrast to a previous scheme [J. W. Pan, Nature (London) 410, 1067 (2001)]] that relied on ideal single-pair sources. The present scheme makes use of spatial entanglement in order to purify polarization entanglement. Surprisingly, spatial entanglement as an additional resource also leads to a substantial improvement in entanglement output compared to the previous scheme.
authors.affiliation: Centre for Quantum Computation, University of Oxford, Parks Road, United Kingdom.
authors.forename: Christoph
authors.initials: C
authors.lastname: Simon
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Pan