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Hybrid Long-Distance Entanglement Distribution Protocol

Mon, 2011-02-14 16:55 - Q-Essence Coordinator
Date: 
2010-10-11
Author(s): 

J. B. Brask, I. Rigas, E. S. Polzik, U. L. Andersen, and A. S. Sørensen

Reference: 

Phys. Rev. Lett. 105, 160501 (2010)

URL: 

http://link.aps.org/doi/10.1103/PhysRevLett.105.160501

We propose a hybrid (continuous-discrete variable) quantum repeater protocol for long-distance entanglement distribution. Starting from states created by single-photon detection, we show how entangled coherent state superpositions can be generated by means of homodyne detection. We show that near-deterministic entanglement swapping with such states is possible using only linear optics and homodyne detectors, and we evaluate the performance of our protocol combining these elements.

 

Giant Stark effect in the emission of single semiconductor quantum dots

Mon, 2011-02-14 16:49 - Q-Essence Coordinator
Date: 
2010-07-19
Author(s): 

Anthony J. Bennett, Raj B. Patel, Joanna Skiba-Szymanska, Christine A. Nicoll, Ian Farrer, David A. Ritchie, and Andrew J. Shields

Reference: 

Appl. Phys. Lett. 97, 031104 (2010)

URL: 

http://link.aip.org/link/doi/10.1063/1.3460912

We study the quantum-confined Stark effect in single InAs/GaAs quantum dots embedded within a AlGaAs/GaAs/AlGaAs quantum well. By significantly increasing the barrier height we can observe emission from a dot at electric fields of 500 kV cm−1, leading to Stark shifts of up to 25 meV. Our results suggest this technique may enable future applications that require self-assembled dots with transitions at the same energy.

 

Bound Nonlocality and Activation

Mon, 2011-02-14 16:09 - Q-Essence Coordinator
Date: 
2011-01-10
Author(s): 

Nicolas Brunner, Daniel Cavalcanti, Alejo Salles, and Paul Skrzypczyk

Reference: 

Phys. Rev. Lett. 106, 020402 (2011)

URL: 

http://link.aps.org/doi/10.1103/PhysRevLett.106.020402

We investigate nonlocality distillation using measures of nonlocality based on the Elitzur-Popescu-Rohrlich decomposition. For a certain number of copies of a given nonlocal box, we define two quantities of interest: (i) the nonlocal cost and (ii) the distillable nonlocality. We find that there exist boxes whose distillable nonlocality is strictly smaller than their nonlocal cost. Thus nonlocality displays a form of irreversibility which we term “bound nonlocality.” Finally, we show that nonlocal distillability can be activated.

Noisy evolution of graph-state entanglement

Sat, 2011-02-12 14:03 - Q-Essence Coordinator
Date: 
2010-09-21
Author(s): 

L. Aolita, D. Cavalcanti, R. Chaves, C. Dhara, L. Davidovich, and A. Acín

Reference: 

Phys. Rev. A 82, 032317 (2010)

URL: 

http://link.aps.org/doi/10.1103/PhysRevA.82.032317

"Quantum cryptography is not picky, physicists prove" research at Faculty of Physics, University of Warsaw

Thu, 2011-02-03 19:04 - Q-Essence Coordinator

An article in AlphaGalileo portal on the latest experiment with photonic entanglement at Faculty of Physics, University of Warsaw. This research conducted by Polish physicists was also supported by Q-ESSENCE project.

 

Q-ESSENCE support for young researchers

Wed, 2011-02-02 17:38 - Q-Essence Coordinator
Summary: 

Q-ESSENCE MTC has agreed to support 5
scholarships related to the 'SUSSP67: Quantum Information &  Coherence' summer school in Scotland.

The preference is given to researchers/students from Q-ESSENCE members. Application deadline: end of February. More information at:

http://sussp67.phys.strath.ac.uk/

 

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