Efficient two-step entanglement concentration for arbitraryWstates

Error exponents for entanglement concentration

Consider entanglement concentration schemes that convert n identical copies of a pure state into a maximally entangled state of a desired size with success probability being close to one in the asymptotic limit. We give the distillable entanglement, the number of Bell pairs distilled per copy, as a function of an error exponent, which represents the rate of decrease in failure probability as n ...

Qubit and Entanglement assisted Optimal Entanglement Concentration

We present two methods for optimal entanglement concentration from pure entangled states by local actions only. However a prior knowledge of the Schmidt coefficients is required. The first method is optimally efficient only when a finite ensemble of pure entangled states are available whereas the second method realizes the single pair optimal concentration probability. We also propose an entang...

A Practical Scheme for Entanglement Concentration

We present a realistic purification scheme for pure non-maximally entangled states. In the scheme, Alice and Bob at two distant parties first start with two shared but less entangled photon pairs to produce a conditional four-photon GHZ state, then perform a 45◦ polarization measurement onto one of the two photons at each party such that the remaining two photons are projected onto a maximally ...

Oracally efficient two-step estimation for additive regression

Retraction: Efficient Concentration Protocols for the Single-Photon Entanglement State with Polarization Feature

The Journal and Authors retract the 10 March 2017 article cited above for the following reasons provided by the authors: Following publication, the authors realized a fundamental conceptual error in the article’s equations. This error extends from Equations (3)–(5) and negates the derivations of the equations and descriptions in the article. The Journal and Chief Editors concur that the reasons...