QUROPE Quantum Information Processing and Communication in Europe

J. Aasi, et al.
Nature Photonics 7, 613–619 (2013)

A global network of observatories is seeking to directly detect gravitational waves using precision laser
interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the
attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task.

A. Reiserer, S. Ritter and G. Rempe
Science 342, 1349-1351 (2013)

We demonstrate cooling of the motion of a single neutral atom confined by a dipole trap inside a high-finesse
optical resonator. Cooling of the vibrational motion results from electromagnetically induced transparency
(EIT)-like interference in an atomic \Lambda-type configuration, where one transition is strongly coupled to the cavity
mode and the other is driven by an external control laser. Good qualitative agreement with the theoretical
predictions is found for the explored parameter ranges. Further, we demonstrate EIT cooling of atoms in the

It is widely believed that next-generation electronic devices will exploit the quantum mechanical nature of electrons, as opposed to the classical operating principles of current electronics. This is one of the leading paradigms at the origin of quantum spintronics, a developing field whose goal is to create useful device functionalities out of the spin degree of freedom of electrons. So far, quantum spintronics has remained a matter of basic research.

On the 22nd of January 2014, Neelie KROES, the current Vice-President of the European Commission and responsible for the Digital Agenda, delivered a speech entitled "A vision for Europe" at the World Economic Forum held in Davos.

Specific challenge: Devices that exploit quantum phenomena such as superposition and entanglement have the potential to enable radically new technologies. Several promising directions are now well known, for instance in quantum computation and simulation, quantum communication, quantum metrology and sensing. However, overcoming basic scientific challenges as well as bridging from the scientific results to concrete engineering technologies has proved difficult.

In a recent publication in Scientific Reports the group led by SOLID partner Jonathan Finley at the Walter Schottky institut of TUM achieve fast, all optical spin control in a single quantum dot without magnetic fields.

In their recent article in Science Magazine the SOLID group at KIT led by Alexey Ustinov demonstrated experimentally that minute deformation of the oxide barrier changes the energies of the atomic tunneling systems, and measured these changes by microwave spectroscopy of the superconducting qubit through coherent interactions between these two quantum systems.

IThe SOLID group of Lieven Vandersypen recently published a paper in Physical Review Letters in which they investigated phonon-induced spin and charge relaxation mediated by spin-orbit and hyperfine interactions for a single electron confined within a double quantum dot. They extract an electron spin relaxation rate that varies nonmonotonically with the detuning between the dots and confirm this model with experiments performed on a GaAs double dot.

The Quantronics group at SOLID partner CEA have recently published a paper in Physical Review Letters in wihch they measure the quantum fluctuations of a pumped nonlinear resonator using a superconducting artificial atom as an in situ probe. The qubit excitation spectrum provided access to the frequency and amount of excitation of the intracavity field fluctuations, from which we infer its effective temperature.