Entanglement criteria for all bipartite Gaussian states.

@article{Giedke2001EntanglementCF,
  title={Entanglement criteria for all bipartite Gaussian states.},
  author={G{\'e}za Giedke and Barbara Kraus and Maciej Lewenstein and Juan Ignacio Cirac},
  journal={Physical review letters},
  year={2001},
  volume={87 16},
  pages={
          167904
        }
}
We provide a necessary and sufficient condition for separability of Gaussian states of bipartite systems of arbitrarily many modes. The condition provides an operational criterion since it can be checked by simple computation. Moreover, it allows us to find a pure product-state decomposition of any given separable Gaussian state. We also show that all bipartite Gaussian states with nonpositive partial transpose are distillable. 

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References

SHOWING 1-10 OF 27 REFERENCES

Improvement on teleportation of continuous variables by photon subtraction via conditional measurement

We show that the recently proposed scheme of teleportation of continuous variables [S.L. Braunstein and H.J. Kimble, Phys. Rev. Lett. 80, 869 (1998)] can be improved by a conditional measurement of

Bound entanglement and continuous variables

TLDR
It is pointed out that the "entanglement witnesses" and positive maps revealing the corresponding bound entanglement can easily be constructed and a new many parameter family of bound entangled states with positive partial transpose is obtained.

Peres-horodecki separability criterion for continuous variable systems

  • Simón
  • Mathematics
    Physical review letters
  • 2000
TLDR
The Peres-Horodecki criterion of positivity under partial transpose is studied in the context of separability of bipartite continuous variable states and turns out to be a necessary and sufficient condition for separability.

Quantum Repeaters: The Role of Imperfect Local Operations in Quantum Communication

TLDR
This work presents a scheme of a quantum repeater that connects a string of (imperfect) entangled pairs of particles by using a novel nested purification protocol, thereby creating a single distant pair of high fidelity.

Inseparable Two Spin- 1 2 Density Matrices Can Be Distilled to a Singlet Form

A quantum system is called inseparable if its density matrix cannot be written as a mixture of product states. In this Letter we apply the separability criterion, local filtering, and Bennett et al.

Transition probabilities between quasifree states

We obtain a general formula for the transition probabilities between any state of the C* algebra of the canonical commutation relations (CCR-algebra) and a squeezed quasifree state (Theorem III.1).

Distillability and partial transposition in bipartite systems

Institut fu¨r Theoretische Physik, Universit¨at Hannover, D-30167 Hannover, Germany(February 1, 2008)We study the distillability of a certain class of bipartitedensity operators which can be obtained

Mixed-State Entanglement and Distillation: Is there a “Bound” Entanglement in Nature?

It is shown that if a mixed state can be distilled to the singlet form it must violate partial transposition criterion [A. Peres, Phys. Rev. Lett. 76, 1413 (1996)]. It implies that there are two