News

EPJ B Highlight - On-demand conductivity for graphene nanoribbons

Details: Published on 05 November 2014

Sketch of a kicked zigzag graphene nanoribbon. © D. Babajanov *et al.*

Physicists from Uzbekistan and Germany have devised a theoretical model to tune the conductivity of graphene zigzag nanoribbons using ultra-short pulses

Physicists have, for the first time, explored in detail the time evolution of the conductivity, as well as other quantum-level electron transport characteristics, of a graphene device subjected to periodic ultra-short pulses. To date, the majority of graphene studies have considered the dependency of transport properties on the characteristics of the external pulses, such as field strength, period or frequency. The new findings have now been published in EPJ B by Doniyor Babajanov from the Turin Polytechnic University in Tashkent, Uzbekistan, and colleagues. These results may help to develop graphene-based electronic devices that only become conductors when an external ultra-short pulse is applied, and are otherwise insulators.

EPJ D Highlight - Plasma: Casimir and Yukawa mesons

Details: Published on 29 October 2014

Energy correction factor for two gold plates in the absence of any intervening plasma. © Ninham *et al.*

The Casimir electromagnetic fluctuation forces across plasmas are analogous to so-called weak nuclear interaction forces, as new findings show

A new theoretical work establishes a long-sought-after connection between nuclear particles and electromagnetic theories. Its findings suggests that there is an equivalence between generalised Casimir forces and what are referred to as weak nuclear interactions between protons and neutrons. The Casimir forces are due to the quantisation of electromagnetic fluctuations in vacuum, while the weak nuclear interactions are mediated by subatomic scale particles, originally called mesons by Yukawa. These findings by Barry Ninham from the Australian National University, in Canberra, and European colleagues, have now been published in EPJ D.

EPJ A Highlight - Achieving high resolution in binary nuclear reactions with outgoing fast neutrons – at last!

Details: Published on 28 October 2014

To date, the two-nucleon pick-up and stripping counterparts of the (p,t) and (t,p) reactions, the (³He,n) and (n, ³He) reactions, have been poorly investigated due to the difficulty in performing high-resolution measurements of fast-neutron energies. The best time-of-flight (³He,n) measurements report resolutions not better than 250 keV. This lack of experimental resolution has hindered a full understanding of the role of proton pairing in nuclei.

EPJ E Highlight - Ion adsorption matter in biology

Details: Published on 28 October 2014

New systematic study of the electrical properties of model lipid membranes could improve our understanding of biological cells and opens new possibilities for medical diagnostics

Biological membranes are mainly composed of lipid bilayers. Gaining a better understanding of adsorption of solution ions onto lipid membranes helps clarify functional processes in biological cells. Now, a new study provides a quantitative description of the equilibria between lipid membranes and surrounding solution ions. Joanna Kotyńska and Zbigniew Figaszewski from the University of Bialystok, Poland, are the authors of a study describing these findings, just published in EPJ E. In addition to shedding some light on biological processes, these results could also have implications for, among other things, the future development of medical diagnostics.

EPJ B Video - EPJ B Colloquia, introductions to new research directions

Details: Published on 22 October 2014

Luciano Colombo explains the benefits of colloquia papers in EPJ B.

EPJB Colloquium - Embedded nanocrystals get reshaped by ion beams

Details: Published on 20 October 2014

A new Colloquium paper published in EPJ B looks at ion irradiation techniques as a means to control the structure of nanoclusters and nanocrystals embedded in solid materials, such as silica or silicon.

EPJ E Highlight - Thermodiffusion in weightlessness

Details: Published on 20 October 2014

alt — Flow pattern 2 min after the start of vibrations. © Y. Gaponenko *et al.*

Zero gravity experiments on the International Space Station shed some light on thermodiffusion effects, relevant to the oil and gas industry and global warming prevention processes

Thermodiffusion, also called the Soret effect, is a mechanism by which an imposed temperature difference establishes a concentration difference within a mixture. Two studies by Belgian scientists from the Free University of Brussels, recently published in EPJ E, provide a better understanding of such effects. They build on recent experimental results from the IVIDIL—Influence Vibration on Diffusion in Liquids—research project performed on the International Space Station under microgravity to avoid motion in the liquids.

EPJ D Highlight - Quantum holograms as atomic scale memory keepsake

Details: Published on 15 October 2014

Set up of the experiment showing the orthogonal side illumination. © A. N. Vetlugin *et al.*

A new theoretical study demonstrates for the first time that quantum holograms could be a candidate for becoming quantum information memory

Russian scientists have developed a theoretical model of quantum memory for light, adapting the concept of a hologram to a quantum system. These findings are included in study just published in EPJ D, by Anton Vetlugin and Ivan Sokolov from St. Petersburg State University in Russia. The authors demonstrate for the first time, that it is theoretically possible to retrieve, on demand, a given portion of the stored quantised light signal of a holographic image—set in a given direction in a given position in time sequence.

EPJ D Colloquium: Recent positron-atom cross section measurements and calculations

Details: Published on 14 October 2014

In this EPJ D colloquium paper, the authors review a cross-section of recent results relating to low-energy positron scattering from atomic targets, and present a comparison of the latest measurements and calculations for positron collisions with the noble gases, together with a brief update on the newest studies addressing other atomic targets. In particular, they provide an overview of the work that has been done in examining elastic scattering, positronium formation, direct and total ionisation, as well as total scattering, at typical energies ranging from 0.1 eV to a few hundred eV.

EPJ Plus Highlight - Electric/magnetic dipole in an electromagnetic field: force, torque and energy

Details: Published on 08 October 2014

How does an electric (or magnetic) dipole behave in an electromagnetic field, when its velocity becomes comparable with the speed of light?

This problem has been solved for the first time in a paper recently published in EPJ Plus, where novel relativistic effects were found. In particular, it has been shown that the concept of “hidden” momentum of magnetic dipoles in an electric field, being disputable up to date, is strongly required to derive relativistically adequate solutions. Moreover, a novel concept of “latent” momentum of electric dipole should be also involved into the description of dipoles.