It is possible to entangle two photons that have never interacted before by using two down-conversion sources and then subjecting one photon from each entangled pair to a Bell-state measurement. This causes the other two photons, which have never interacted, to become entangled.
Further Links for Consideration
The basics of two-party entanglement
Basics of multiparty entanglement
Basics of secret sharing
We have engineered an entangled state made of two atoms and the cavity mode. The entanglement is produced in a succession of controlled steps addresssing the particles individually. The sequence is fully programmable and could be configured to produce any quantum state. We have chosen here to prepare a triplet of entangled particles of the GHZ type. The entanglement has been demonstrated by experiments performed in two orthogonal basis. The procedure can, in principle, operate on larger numbers of particles, opening the way to new fundamental tests of quantum theory.
Test of the Quantenteleportation
over long distances in the duct system of Vienna
Quantity of experiment and the Foundations OF Physics
Professor Anton Zeilinger
Quantum physics questions the classical physical conception of the world and also the everyday life understanding, which is based on our experiences, in principle. In addition, the experimental results lead to new future technologies, which a revolutionizing of communication and computer technologies, how we know them, promise.
In order to exhaust this technical innovation potential, the project "Quantenteleportation was brought over long distances" in a co-operation between WKA and the working group by Professor Anton Zeilinger into being. In this experiment photons in the duct system "are teleportiert" of Vienna, i.e. transferred, the characteristics of a photon to another, removed far. First results are to be expected in the late summer 2002.