Purification of Noisy Entanglement and Faithful Teleportation via Noisy Channels
Charles H. Bennett,Gilles Brassard,Sandu Popescu,Benjamin Schumacher,John A. Smolin,William K. Wootters +5 more
TLDR
Upper and lower bounds on the yield of pure singlets ($\ket{\Psi^-}$) distillable from mixed states $M$ are given, showing $D(M)>0$ if $\bra{Psi-}M\ket-}>\half$.Abstract:
Two separated observers, by applying local operations to a supply of not-too-impure entangled states (e.g., singlets shared through a noisy channel), can prepare a smaller number of entangled pairs of arbitrarily high purity (e.g., near-perfect singlets). These can then be used to faithfully teleport unknown quantum states from one observer to the other, thereby achieving faithful transmission of quantum information through a noisy channel. We give upper and lower bounds on the yield $D\left(M\right)$ of pure singlets $(|{\ensuremath{\Psi}}^{\ensuremath{-}}〉)$ distillable from mixed states $M$, showing $D\left(M\right)g0$ if $〈{\ensuremath{\Psi}}^{\ensuremath{-}}|M|{\ensuremath{\Psi}}^{\ensuremath{-}}〉g\frac{1}{2}$.read more
Citations
More filters
Journal ArticleDOI
Experimental extraction of secure correlations from a noisy private state.
Krzysztof Dobek,Krzysztof Dobek,Michał Karpiński,Rafał Demkowicz-Dobrzański,Konrad Banaszek,Konrad Banaszek,Paweł Horodecki +6 more
TL;DR: Experimental generation of a noisy entangled four-photon state that exhibits a separation between the secure key contents and distillable entanglement, a hallmark feature of the recently established quantum theory of private states is reported.
Journal ArticleDOI
Characterization of distillability of entanglement in terms of positive maps
TL;DR: In this paper, a necessary and sufficient condition for one-distillability is formulated in terms of decomposable positive maps, and a connection between a number of existing results is established, which leads to an elementary proof for the characterization of distillability of two-positive maps.
Journal ArticleDOI
Generation and interrogation of a pure nuclear spin state by parahydrogen-enhanced NMR spectroscopy: a defined initial state for quantum computation.
Damir Blazina,Simon B. Duckett,T. K. Halstead,Christopher M. Kozak,Richard J. K. Taylor,Muhammad Sabieh Anwar,Jonathan A. Jones,Hilary A. Carteret +7 more
TL;DR: A number of studies are described used to establish that parahydrogen can be used to prepare a two‐spin system in a pure state, which is suitable for implementing NMR quantum computation.
Journal ArticleDOI
Entanglement concentration with strong projective measurement in an optomechanical system
TL;DR: In this paper, an entanglement concentration scheme based on phonon counting measurements, which can be performed through photon counting of an auxiliary cavity connected to the mechanical resonator, was proposed.
Posted Content
Classical and Quantum Tensor Product Expanders
TL;DR: The classical case is discussed, and it is shown that a classical two-copy expander can be used to produce a quantum expander, giving tight bounds on the expectation value of the largest nontrivial eigenvalue in the quantum case.
References
More filters
Journal ArticleDOI
Concentrating partial entanglement by local operations
TL;DR: Any pure or mixed entangled state of two systems can be produced by two classically communicating separated observers, drawing on a supply of singlets as their sole source of entanglement.
Journal ArticleDOI
Generalized privacy amplification
TL;DR: This paper provides a general treatment of privacy amplification by public discussion, a concept introduced by Bennett, Brassard, and Robert for a special scenario, and yields results on wiretap and broadcast channels for a considerably strengthened definition of secrecy capacity.