title: Robust long-distance entanglement and a loophole-free bell test with ions and photons.
abstract: Two trapped ions that are kilometers apart can be entangled by the joint detection of two photons, each coming from one of the ions, in a basis of entangled states. Such a detection is possible with linear optical elements. The use of two-photon interference allows entanglement distribution free of interferometric sensitivity to the path length of the photons. The present method of creating entangled ions also opens up the possibility of a loophole-free test of Bell's inequalities.
authors.affiliation: Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom.
authors.forename: Christoph
authors.initials: C
authors.lastname: Simon
authors.forename: William T M
authors.initials: WT
authors.lastname: Irvine