QUROPE Quantum Information Processing and Communication in Europe

The newsletter can be found at:

http://cordis.europa.eu/fp7/ict/programme/docs/fp7-fet-nl-08_en.pdf

We experimentally demonstrate a detection scheme suitable for state analysis of single optically trapped atoms in less than 1  μs with an overall detection efficiency η exceeding 98%. The method is based on hyperfine-state-selective photoionization and subsequent registration of the correlated photoion-electron pairs by coincidence counting via two opposing channel electron multipliers.

A quantum memory for light is a key element for the realization of future quantum information networks. Requirements for a good quantum memory are versatility (allowing a wide range of inputs) and preservation of quantum information in a way unattainable with any classical memory device. Here we demonstrate such a quantum memory for continuous-variable entangled states, which play a fundamental role in quantum information processing.

The signature of coherent coupling between two quantum states is an anticrossing in their energies as one is swept through the other. In single semiconductor quantum dots containing an electron–hole pair the eigenstates form a two-level system that can be used to demonstrate quantum effects in the solid state, but in all previous work these states were independent. Here we describe a technique to control the energetic splitting of these states using a vertical electric field, facilitating the observation of coherent coupling between them.

The French magazine La Recherche distinguished Prof. Antonio Acin (ICFO, Q-ESSENCE Partner), Prof. Serge Massar and  Dr. Stefano Pironio (Université Libre de Bruxelles, Belgium) with an award meant to highlight exceptional work during the year carried out in the fracophone region. The title of the contribution, based on the scientific article that appeared in Nature in April, is “La certitude de l’aléa quantique”.

In the quantum regime information can be copied with only a finite fidelity. This fidelity gradually increases to 1 as the system becomes classical. In this Letter we show how this fact can be used to directly measure the amount of radiated power. We demonstrate how these principles can be used to build a practical primary standard.

We show how continuous matrix product states of quantum fields can be described in terms of the dissipative nonequilibrium dynamics of a lower-dimensional auxiliary boundary field by demonstrating that the spatial correlation functions of the bulk field correspond to the temporal statistics of the boundary field.

Prof. Silberhorn leads the integrated quantum optics group in the Department of Physics.  

Congratulations!

ID Quantique and Siemens IT Solutions and Services have deployed the first commercial application of a quantum cryptography project in the Netherlands. The qualification project relates to the data transfer via optical fiber connections - with high bandwidth and availability demands – between the data centers of the Siemens offices in The Hague and Zoetermeer.