- Published on 10 August 2012
First quantum cloning machine to produce four copiesXi-Jun Ren and Yang Xiang from Henan Universities in China, in collaboration with Heng Fan at the Institute of Physics of the Chinese Academy of Sciences, have produced a theory for a quantum cloning machine able to produce several copies of the state of a particle at atomic or sub-atomic scale, or quantum state, in an article published in EPJ D. This could have implications for quantum information processing methods used, for example, in message encryption systems.
- Published on 15 September 2011
Scientists from the University of Vienna’s Faculty of Physics in Austria recently gave a theoretical description of teleportation phenomena in sub-atomic scale physical systems, in a publication in the European Physical Journal D.
For the first time, the Austrian team proved that mathematical tools give us the freedom to choose how to separate out the constituting matter of a complex physical system by selectively analysing its so-called quantum state. That is the state in which the system is found when performing measurement, which can either be entangled or not.
- Published on 16 May 2011
Quantum information processing requires logical operations with multiple quantum bits. One route to this goal is controlling each qubit with a time-dependent external magnetic field. In this recent paper published in EPJ D, Heule et al. describe ways to perform logical operations on an ENTIRE superconducting qubit chain by controlling just ONE of the end qubits of the chain.
- Published on 31 March 2011
Quantum mechanical measurements are often assumed to be accurate and repeatable. However, due to a fundamental result of Wigner (1952) and Araki and Yanase (1961), we now know that there are limitations to these properties in the presence of aconserved quantity that does not commute with the observable to be measured. Despite its importance and impact on quantum technologies, the full scope of this so-called WAY theorem has remained unclear.
EPJ D - Feshbach resonances in the 6Li-40K Fermi-Fermi mixture: Elastic versus inelastic interactions
- Published on 30 March 2011
(Cold Quantum Matter - EuroQUAM special issue)
Ultracold mixtures of two fermionic species hold great promise for synthesizing novel types of few and many-body quantum states. Magnetically tunable Feshbach resonances are the key to controlling the interaction in such systems. In this article in EPJD, Naik et al. present a state-of-the-art characterization of Feshbach resonances in the Fermi-Fermi mixture of 6Li-40K atoms, in particular concerning the interplay of both elastic and inelastic scattering.
- Published on 28 March 2011
Helium nanodroplets provide a unique matrix for the spectroscopy of embedded atom species. In this recent paper in EPJD, Bünermann and Stienkemeier demonstrate a new model of how effects such as droplet shrinking, momentum transfer and cluster desorption affect the pick-up statistics of alkali atoms in helium nanodroplets.
- Published on 03 January 2011
A photon is not a point: its wavepacket stretches out in space. In the classical limit, this spatial profile is governed by Maxwell's equations, and reshaping it has been a goal in optics since Galileo's invention of the telescope. In this paper, Morizur and his colleagues describe a new Unitary Programmable Mode Converter, a device capable of changing the spatial shape of quantum light at will without introducing loss in the beam.
- Published on 12 October 2010
A group of researchers in Greifswald, Germany, measured the electron concentration and electron temperature in the active discharge zone of a self-organized plasma jet. Self-organized discharge patterns are shown as time averaged top view in the picture.
Miniaturized non-thermal plasma jets are an emerging technique for surface treatments at ambient pressure, such as cleaning, activation, etching, films deposition and more.
The authors of this EPJ D paper used two independent approaches: spectroscopy and a two-dimensional fluid model calculation of a discharge filament. The results from the two methods are consistent and indicate electron concentrations between 2.2 and 3.3×1014 cm-3. This work represents a first step towards a thorough physical description of the discharge dynamics and energy transport to gain a better understanding of self-organization effects in non thermal plasma jets.