Free-Space distribution of entanglement and single photons over 144 km

@article{Ursin2006FreeSpaceDO,
  title={Free-Space distribution of entanglement and single photons over 144 km},
  author={Rupert Ursin and F. Tiefenbacher and Tobias Schmitt-Manderbach and Henning Weier and Thomas Scheidl and Michael Lindenthal and Bibiane Blauensteiner and Thomas Jennewein and Josep Perdigues and Pavel Trojek and B. Oemer and Martin Fuerst and Michael Meyenburg and John G. Rarity and Zoran Sodnik and Cesare Barbieri and Harald Weinfurter and Anton Zeilinger},
  journal={Nature Physics},
  year={2006}
}
Quantum Entanglement is the essence of quantum physics and inspires fundamental questions about the principles of nature. Moreover it is also the basis for emerging technologies of quantum information processing such as quantum cryptography, quantum teleportation and quantum computation. Bell's discovery, that correlations measured on entangled quantum systems are at variance with a local realistic picture led to a flurry of experiments confirming the quantum predictions. However, it is still… 

Two Atoms Announce Their Long-Distance Relationship

TLDR
The quantum entanglement of two atoms 20 m apart, verified by a secondary process, can enable long-distance quantum communications and is described with two individual atoms held in laser traps and separated by a distance of 20 m.

Experiments on Multiphoton Entanglement

Entanglement lies at the heart of quantum mechanics and challenged the intuition of physicists ever since it was discovered. At the same time, it is a powerful tool that serves as a key resource for

Characterizing quantum channels with non-separable states of classical light

High-dimensional entanglement with spatial modes of light promises increased security and information capacity over quantum channels. Unfortunately, entanglement decays due to perturbations,

Quantum entanglement

All our former experience with application of quantum theory seems to say that what is predicted by quantum formalism must occur in the laboratory. But the essence of quantum formalism— entanglement,

Quantum entanglement of angular momentum states with quantum numbers up to 10,010

TLDR
The results show how complex the structure of entangled photons can be and hint at the large information content a single quantum system is able to carry, and highlight OAM as a promising way to increase the information capacity of a single photon.

On Free Space Quantum Key Distribution and its Implementation with a Polarization-Entangled Parametric Down Conversion Source

This thesis describes the deployment of a free-space quantum key distribution system across the University of Waterloo campus. The quantum key distribution system has the ability to provide

Experimental demonstration of a BDCZ quantum repeater node

TLDR
This work realizes entanglement swapping with storage and retrieval of light, a building block of the BDCZ quantum repeater, and establishes the essential element needed to realize quantum repeaters with stationary atomic qu bits as quantum memories and flying photonic qubits as quantum messengers.

Twisted photon entanglement through turbulent air across Vienna

TLDR
It is shown that it is possible to distribute quantum entanglement of spatially structured photons over a free-space intracity link of 3 km, and the access to four orthogonal quantum channels in which entanglements can be distributed over large distances.

Improving entangled free-space quantum key distribution in the turbulent atmosphere

By now, free-space quantum key distribution (QKD) has seen many experiments validate the possibility of its implementation in various real world scenarios[1–4]. Recently, particular interest has

Quantum teleportation over 143 kilometres using active feed-forward

TLDR
The quality of the quantum teleportation procedure without feed-forward is confirmed, well beyond the classical limit of two-thirds, and the maturity and applicability of such technologies in real-world scenarios are verified, in particular for future satellite-based quantum teleportation.
...

References

SHOWING 1-10 OF 33 REFERENCES

Experimental free-space distribution of entangled photon pairs over 13 km: towards satellite-based global quantum communication.

TLDR
The distributed entangled photon source is exploited to demonstrate the Bennett-Brassard 1984 quantum cryptography scheme and the distribution distance achieved is for the first time well beyond the effective thickness of the aerosphere, hence presenting a significant step towards satellite-based global quantum communication.

Experimental Free-Space Distribution of Entangled Photon Pairs over a Noisy Ground Atmosphere of 13km

We report free-space distribution of entangled photon pairs over a noisy ground atmosphere of 13km. It is shown that the desired entanglement can still survive after the two entangled photons have

Deterministic quantum teleportation of atomic qubits

TLDR
Un unconditional teleportation of massive particle qubits using atomic (9Be+) ions confined in a segmented ion trap is reported, which achieves an average fidelity of 78 per cent, which exceeds the fidelity of any protocol that does not use entanglement.

Proof-of-concept experiments for quantum physics in space

Quantum physics experiments in space using entangled photons and satellites are within reach of current technology. We propose a series of fundamental quantum physics experiments that make

Security of quantum key distribution with entangled photons against individual attacks

TLDR
A proof of security which applies to realistic sources, and to untrustable sources which can be placed outside the labs of the two receivers, is presented, and it is shown that BBM92 has potential for much longer communication distances, up to 170 km, in the presence of realistic experimental imperfections.

Experimental demonstration of quantum correlations over more than 10 km

Energy and time entangled photons at a wavelength of 1310 nm are produced by parametric down-conversion in a ${\mathrm{KNbO}}_{3}$ crystal and are sent into all-fiber interferometers using a

Experimental quantum teleportation

TLDR
It is shown that during teleportation, one of a pair of entangled photons are subjected to a measurement such that the second photon of the entangled pair acquires the polarization of the initial photon.

Quantum computation

The theory of quantum computation can be constructed from the abstract study of anyonic systems. In mathematical terms, these are unitary topological modular functors. They underlie the Jones

Quantum cryptography with entangled photons

TLDR
A novel key distribution scheme is implemented using Wigner's inequality to test the security of the quantum channel, and a variant of the BB84 protocol is realized.

Long-Distance Free-Space Distribution of Quantum Entanglement

We demonstrate the distribution of quantum entanglement via optical free-space links to independent receivers separated by 600 m, with no line of sight between each other. A Bell inequality between