QUROPE Quantum Information Processing and Communication in Europe

We show how to use the radiation pressure optomechanical coupling between a mechanical oscillator and an optical cavity field to generate in a heralded way a single quantum of mechanical motion (a Fock state). Starting with the oscillator close to its ground state, a laser pumping the upper motional sideband produces correlated photon-phonon pairs via optomechanical parametric down-conversion.

Monitoring a mechanical object’s motion, even with the gentle touch of light, fundamentally alters its dynamics.

Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of nature, and moreover also enables genuinely new protocols for quantum information processing.

In transport experiments the quantum nature of matter becomes directly evident when changes in conductance occur only in discrete steps, with a size determined solely by Planck's constant h. The observations of quantized steps in the electric conductance have provided important insights into the physics of mesoscopic systems and allowed for the development of quantum electronic devices. Even though quantized conductance should not rely on the presence of electric charges, it has never been observed for neutral, massive particles.

The paper, authored by, A. Celi, P. Massignan, J. Ruseckas, N. Goldman, I.B. Spielman, G. Juzeliunas, M. Lewenstein, has been published the 28th January 2014 on Phys. Rev. Lett. 112, 043001 (2014)

The paper, authored by N. Killoran, M. Cramer and M. B.

Invited Speakers

The paper, authored by G. Waldherr, Y. Wang, S. Zaiser, M. Jamali, T. Schulte-Herbrüggen, H. Abe, T. Ohshima, J. Isoya, J.F. Du, P. Neumann, J. Wrachtrup, has been published on the 13th February 2014 on Nature 506, 204 (2014)

The program of the 6th winterschool on quantum communications deals with quantum cryptography, quantum computing and quantum repeaters. The goal of this event is to introduce this exciting topic in a relaxed and stimulating atmosphere to a general audience of physicists and computer scientists with little or no background in practical quantum communications. Special emphasis will be placed on practical aspects of quantum communications, such as the implementation of quantum key distribution systems and quantum repeaters, as well as concrete steps towards a quantum computer.