2015 Impact factor 1.208
Atomic, Molecular, Optical and Plasma Physics

News / Highlights / Colloquium

EPJ D Highlight - The key to ion beams’ polarisability

Ion beams are used as a source for dopant atoms in semiconductor manufacturing. © Hornpipe, Dreamstime Stock Photos & Stock Free Images

Polarisability for series of multi-electron ions is now available

Polarisability determines the force with which an inhomogeneous external electric field acts on the ions of an ion beam. However, it can be quite tricky to obtain accurate values for this force. Now, two German theoretical chemists, Volker Koch from Bielefeld University and Dirk Andrae from the Free University Berlin, have devised formulas providing the polarisability of atomic ions as a function of their total charge number. Their findings, about to be published in EPJ D, have implications for many applications, ranging from the use of ion beams for research purposes or as a source for dopant atoms in semiconductor manufacturing to the modelling of planetary and stellar atmospheres.

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EPJ D Highlight - Elucidating energy shifts in optical tweezers

Optical tweezers have many uses on quantum applications. © VU University Amsterdam

Physicists are providing an all-in-one guide to help calculate the effect the use of optical tweezers has on the energy levels of atoms under study

A small piece of paper sticks to an electrically charged plastic ruler. The principle of this simple classroom physics experiment is applied at the microscopic scale by so-called optical tweezers to get the likes of polystyrene micro-beads and even living cells to “stick” to a laser beam, or to trap atoms at ultra-low temperatures. Physicist Fam Le Kien and his colleagues from the Institute of Atomic and Subatomic Physics of the Vienna University of Technology, Austria, provide a comprehensive manual with general theoretical tools, definitions, and spectroscopic data sets for calculating the energy levels of atoms, which are modified by light emanating from optical tweezers, in a study just published in EPJ D.

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EPJ D Highlight - Ephemeral vacuum particles induce speed-of-light fluctuations

Light propagating in a vacuum travels at a speed that fluctuates due to ephemeral particle pairs. © Ilco

New research shows that the speed of light may not be fixed after all, but rather fluctuates

Two EPJ D papers challenge established wisdom about the nature of vacuum. In one paper, Marcel Urban from the University of Paris-Sud, located in Orsay, France and his colleagues identified a quantum level mechanism for interpreting vacuum as being filled with pairs of virtual particles with fluctuating energy values. As a result, the inherent characteristics of vacuum, like the speed of light, may not be a constant after all, but fluctuate. Meanwhile, in another study, Gerd Leuchs and Luis L. Sánchez-Soto, from the Max Planck Institute for the Physics of Light in Erlangen, Germany, suggest that physical constants, such as the speed of light and the so-called impedance of free space, are indications of the total number of elementary particles in nature.

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EPJ D Highlight - New taxonomy of platinum nanoclusters

Energy landscape of Platinum nanoclusters. © L. Pavan et al.

The unexpected diversity of metallic nanoclusters’ inner structure has now been catalogued into families

Physicists have gained new insights into the inner intricacies of the structural variations of metallic nanoclusters. This work by Luca Pavan, Cono Di Paola and Francesca Baletto from King's College London, UK, has just been published in EPJ D. It takes us one step closer to tailoring on-demand characteristics of metallic nanoparticles. Indeed, the geometric structure of these nanoclusters influences their chemical and physical properties, which differ from those of individual molecules and of bulk metals.

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EPJ D has a new Editor in Chief for quantum optics and quantum information

 Vladimir Bužek new Editor-in-Chief of EPJ D as of 1 January 2013

From January 2013 Vladimir Bužek succeeds Claude Fabre as Editor in Chief of EPJ D with responsibility for papers in quantum optics, quantum information and related topics.

Prof. Dr. Bužek graduated from the Moscow State University (both MSc and PhD) in theoretical physics. His research interests are focused on quantum optics, quantum information sciences, quantum measurement theory and foundations of quantum mechanics. He has been the head of the Research Center for Quantum Information at the Slovak Academy of Sciences and holds a professorial position at the Faculty of Informatics of the Masaryk University in Brno, Czech Republic.

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EPJ D Highlight - Fusion helped by collision science

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The ITER fusion reactor’s inner wall containing beryllium among other constituents. © ITER Organisation

Understanding the mechanisms of electron-molecule collisions could help predict the operations inside the fusion chamber of the ITER reactor

An international team of physicists has calculated the efficiency of a reaction involving an incoming electron kicking out an electron from the metal beryllium (Be) or its hydrogen compound molecules, in an article just published in EPJ D. The efficiency, which partly depends on the electron’s incoming speed, is encapsulated in a quantity referred to as electron-impact ionisation cross sections (EICS). Electron-molecule interactions matter because they occur in a broad range of applications from the simplest like fluorescent lamps to the most complex, for example, in ionised matter found in plasmas such as latest generation screens, the outer space of the universe, and in fusion reactors.

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EPJ D Highlight - May the force be with the atomic probe

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The ratio between the interaction potentials in the bulk and surface models showing that the difference is largest when the atom-surface distance is matched to the screening length. © E.Eizner, B. Horovitz, and C. Henkel

New models suggest devising means of probing a surface at a sub-micrometric level as this will help us understand how electrons’ diffusion affects long-range attractive forces

Theoretical physicist Elad Eizner from Ben Gurion University, Israel, and colleagues created models to study the attractive forces affecting atoms located at a wide range of distances from a surface, in the hundreds of nanometers range. Their results, just published in EPJ D, show that these forces depend on electron diffusion, regardless of whether the surface is conducting or not. Ultimately, these findings could contribute to designing minimally invasive surface probes.

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EPJ D Colloquium – An accurate method to measure scattering non-perturbatively

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Comparison of the experiment and simulation laser induced fluorescence spectrum of hydroxyl. © Qing Xiong

Atomic and molecular collisions occurring at low impact energies and for neutral targets need adequate methods for accurately measuring their scattering properties. Such measures are fundamental to the description of the dynamics of plasmas and provide insight into the long-range Coulomb interactions between charged particles. In the last twenty years many novel non-perturbative approaches have been applied. The time-dependent close-coupling (TDCC) approach, discussed in this EPJD Review, differs fundamentally from previous non-perturbative approaches in that it solves the time-dependent, rather than time-independent, Schr¨odinger equation. This Review provides a detailed description of the application of the time-dependent close-coupling approach to ionising collisions of electrons, photons and ions with small atoms and molecules.

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EPJ D Highlight - Bringing measuring accuracy to radical treatment

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Comparison of the experiment and simulation laser induced fluorescence spectrum of hydroxyl. © Qing Xiong

Significant progress made in evaluating the density of active species used in medical applications of plasma physics could improve the accuracy of treatment

An international team of scientists working at the Plasma Technology research unit at Ghent University, Belgium, has determined for the first time the absolute density of active substances called radicals found in a state of matter known as plasma, in a study just published in EPJ D. These findings could have important implications for medicine—for example, for stimulating tissue regeneration, or to induce a targeted antiseptic effect in vivo without affecting neighbouring tissues.

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EPJ D Highlight - Plasma screens enhanced as disorder strikes

plasma screen
© FreeDigitalPhotos.net

Study looks at ways to improve the quality of matter akin to that found in plasma screens by dissolving its self-organised hexagonal filament structures made of electric discharge.

A new study improves our understanding of plasma sources, a state of matter similar to gas in which a certain portion of the particles are ionised and which are used for example in plasma display panels. These results revealed by physicists from the University of Greifswald, Germany, Robert Wild and Lars Stollenwerk, and are about to be published in EPJD.

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Editors-in-Chief
V. Buzek, H. Kersten and A.V. Solov'yov
It was my pleasure to be given the opportunity of being helpful in the scientific production process of EPJD. I enjoyed the experience as a referee for the journal: it was instructive, and its procedures were clear and simple. You can certainly count on my assistance for future similar appointments.

Luca Argenti

ISSN (Print Edition): 1434-6060
ISSN (Electronic Edition): 1434-6079

© EDP Sciences, Società Italiana di Fisica and Springer-Verlag

Conference announcements

POSMOL 2017

Magnetic Island, Queensland, Australia, 22-24 July 2017