Witnessing single-photon entanglement with local homodyne measurements: analytical bounds and robustness to losses

@article{Ho2012WitnessingSE,
  title={Witnessing single-photon entanglement with local homodyne measurements: analytical bounds and robustness to losses},
  author={Melvyn Ho and Olivier Morin and Jean-Daniel Bancal and Nicolas Gisin and Nicolas Sangouard and Julien Laurat},
  journal={New Journal of Physics},
  year={2012},
  volume={16},
  pages={103035}
}
Single-photon entanglement is one of the primary resources for quantum networks, including quantum repeater architectures. Such entanglement can be revealed with only local homodyne measurements through the entanglement witness presented in Morin et al (2013 Phys. Rev. Lett. 110 130401). Here, we provide an extended analysis of this witness by introducing analytical bounds and by reporting measurements confirming its great robustness with regard to losses. This study highlights the potential of… 

Figures from this paper

Protecting single-photon entanglement with practical entanglement source
TLDR
This paper exploits the practical spontaneous parametric down-conversion (SPDC) source to realize the amplification, and proves that the amplification using the entanglement generated from SPDC source as auxiliary is better than the amplification assisted with single photons.
Tuning quantum channels to maximize polarization entanglement for telecom photon pairs
Quantum networks entangle remote nodes by distributing quantum states, which inevitably suffer from decoherence while traversing quantum channels. Pertinent decoherence mechanisms govern the reach,
Engineering optical hybrid entanglement between discrete- and continuous-variable states
The generation and manipulation of hybrid entanglement of light involving discrete- and continuous-variable states have recently appeared as essential resources towards the realization of
Demonstration of Einstein-Podolsky-Rosen Steering Using Hybrid Continuous- and Discrete-Variable Entanglement of Light.
TLDR
The results illustrate the potential of optical hybrid entanglement for applications in heterogeneous quantum networks that would interconnect disparate physical platforms and encodings and report on suitable steering inequalities.
Heralded noiseless amplification for single-photon entangled state with polarization feature
TLDR
Two single-photon-assisted heralded noiseless amplification protocols are constructed for the single- photon two-mode entangled state and single-Photon three-mode W state, respectively, where the single -photon qubit has an arbitrary unknown polarization feature.
Single photon path entangled states for quantum communication
The main work done along my PhD is related to entangled states composed of a single photon. This state generation requires fewer resources when compared to other entangled states generation.
Observation of micro–macro entanglement of light
experimentally demonstrate the micro‐macro entanglement of light. The macro system involves over a hundred million photons, whereas the micro system is at the single-photon level. We show that
Overcomplete quantum tomography of a path-entangled two-photon state
Path-entangled N-photon states can be obtained through the coalescence of indistinguishable photons inside linear networks. They are key resources for quantum enhanced metrology, quantum imaging, as
Optical Synthesis of Large-Amplitude Squeezed Coherent-State Superpositions with Minimal Resources.
TLDR
A novel versatile protocol that allows the quantum state engineering of heralded optical coherent-state superpositions and will facilitate the use of suchsuperpositions in subsequent protocols, including fundamental tests and optical hybrid quantum information implementations.
Slowing Quantum Decoherence by Squeezing in Phase Space.
TLDR
This work experimentally observes the reduced decoherence of squeezed optical coherent-state superpositions through a lossy channel and introduces a combination of a decaying value and a rate of decay of the Wigner function negativity to quantify the robustness of states.
...
1
2
...

References

SHOWING 1-10 OF 45 REFERENCES
Witnessing trustworthy single-photon entanglement with local homodyne measurements
  • O. Morin, V. D'Auria, N. Sangouard
  • Physics
    2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC
  • 2013
TLDR
This work presents and experimentally test an entanglement witness allowing one not only to say whether a given state is path-entangled but also thatEntanglement lies in the subspace where the optical paths are each filled with one photon at most, i.e. refers to single-photon Entanglement.
Quantum repeaters with entangled coherent states
Entangled coherent states can be prepared remotely by subtracting non-locally a single photon from two quantum superpositions of coherent states, the so-called "Schroedinger's cat" state. Such
Hybrid long-distance entanglement distribution protocol.
TLDR
It is shown how entangled coherent state superpositions can be generated by means of homodyne detection and it is shown that near-deterministic entanglement swapping with such states is possible using only linear optics andHomodyne detectors.
Quantum repeaters based on atomic ensembles and linear optics
TLDR
The theoretical and experimental status quo of this very active field of quantum repeater protocols is reviewed, and the potentials of different approaches are compared quantitatively, with a focus on the most immediate goal of outperforming the direct transmission of photons.
Measurement-induced entanglement for excitation stored in remote atomic ensembles
TLDR
Observations of entanglement between two atomic ensembles located in distinct, spatially separated set-ups are reported, representing significant progress in the ability to distribute and store entangled quantum states.
Towards experimental entanglement connection with atomic ensembles in the single excitation regime
We present a protocol for performing entanglement connection between pairs of atomic ensembles in the single excitation regime. Two pairs are prepared in an asynchronous fashion and then connected
Long-distance quantum communication with atomic ensembles and linear optics
TLDR
It is shown that the communication efficiency scales polynomially with the channel length, and hence the scheme should be operable over very long distances.
Heralded entanglement between atomic ensembles: preparation, decoherence, and scaling.
TLDR
By way of the concurrence, quantitative characterizations are reported for the scaling behavior of entanglement with excitation probability and for the temporal dynamics of various correlations resulting in the decay of entangling.
Spin entanglement, decoherence and Bohm's EPR paradox.
TLDR
For a macroscopic number of particles prepared in a correlated state, spin entanglement and the EPR paradox can be demonstrated using the criteria for efficiencies eta > 1/3 and eta < 2/3 respectively, which indicates a surprising insensitivity to loss decoherence, in a Macroscopic system of ultra-cold atoms or photons.
Optical hybrid approaches to quantum information
TLDR
This article reviews recent hybrid approaches to optical quantum information processing, in which both discrete and continuous degrees of freedom are exploited, potentially adding weak or measurement-induced nonlinearities to the toolbox.
...
1
2
3
4
5
...