1202.5192 (J. Z. Bernád et al.)

Photon-assisted entanglement creation by minimum-error generalized
quantum measurements in the strong coupling regime    [PDF]

J. Z. Bernád, G. Alber

In generalization of the hydbrid quantum repeater model of van Loock et al.
\cite{vanLoock1} we explore possibilities of entangling two distant material
qubits with the help of a single-mode optical radiation field in the strong
quantum electrodynamical coupling regime of almost resonant interaction. The
optimum generalized field measurements are determined which are capable of
preparing a two-qubit Bell state by postselection with minimum error. It is
demonstrated that in the strong coupling regime some of the recently found
limitations of the non-resonant weak coupling regime can be circumvented
successfully due to characteristic quantum electrodynamical quantum
interference effects. In particular, in the absence of photon loss it is
possible to postselect two-qubit Bell states with fidelities close to unity by
a proper choice of the relevant interaction time. Even in the presence of
photon loss this strong coupling regime offers interesting perspectives for
creating spatially well separated Bell pairs with high fidelities and with high
repetition rates which are relevant for future realizations of quantum
repeaters.

View original: http://arxiv.org/abs/1202.5192