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

News / Highlights / Colloquium

EPJ D Highlight - Better material insights with gentle e-beams

An early 2-D EELS of nitrogen.

Great potential for a new, more accurate, tool for using electron collisions to probe matter

There are several ways to change a molecule, chemically or physically. One way is to heat it; another is to bombard it with light particles, or photons. A lesser known method relies on electron collision, or e-beam technology, which is becoming increasingly popular in industry. In a review outlining new research avenues based on electron scattering, Michael Allan from the University of Fribourg, Switzerland and colleagues explain the subtle intricacies of the extremely brief electron-molecule encounter, in particular with gentle, i.e., very low energy electrons. In this paper, which was recently published in EPJ D, the authors describe how the use of very low energy electrons and a number of other performance criteria, make the approach with the so-called Fribourg instrument a more appealing candidate than previously available tools used to study electron collisions.

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EPJ D Highlight - Revisiting trajectories at the quantum scale

The laws of physics governing the macro scale appear to be an approximation of what is happening at the quantum scale. © hywards / Fotolia

The role of statistics in quantum scale observation explains microscale behaviour

There is a gap in the theory explaining what is happening at the macroscopic scale, in the realm of our everyday lives, and at the quantum level, at microscopic scale. In this paper published in EPJ D, Holger Hofmann from the Graduate School of Advanced Sciences of Matter at Hiroshima University, Japan, reveals that the assumption that quantum particles move because they follow a precise trajectory over time has to be called into question. Instead, he claims that the notion of trajectory is a dogmatic bias inherited from our interpretation of everyday experience at the macroscopic scale. The paper shows that trajectories only emerge at the macroscopic limit, as we can neglect the complex statistics of quantum correlations in cases of low precision.

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EPJ D Highlight - How repeated spot microdischarges damage microdevices

Simulated velocity field of the microfilament in the vicinity of the dielectric wall after the train of 150 localised breakdowns

New study blames temperature increase on locally reoccurring discharges in microelectronic devices

In microelectronics, devices made up of two electrodes separated by an insulating barrier are subject to multiple of microdischarges—referred to as microfilaments—at the same spot. These stem from residual excited atoms and ions from within the material, the surface charge deposited on the insulating part of the device, and local temperature build-up. These reoccurences can lead to the creation of pin-holes in the material of the microelectronic devices where they occur, and are due to local reductions in the electric field. Now, Jozef Ráhel and colleagues from Masaryk University in the Czech Republic have elucidated the mechanism of microdischarge reoccurrence, by attributing it to the temperature increase in a single microdischarge. These results were recently published in EPJ D.

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EPJ D Highlight - Bending hot molecules

Japanese scientists have developed a method to study hot carbon dioxide molecules by controlling the likelihood that reactions occur between electrons and hot molecules. vector_master / Fotolia

New model for controlling hot molecules reactions, which are relevant to fusion, space exploration and planetary science

Hot molecules, which are found in extreme environments such as the edges of fusion reactors, are much more reactive than those used to understand reaction studies at ambient temperature. Detailed knowledge of their reactions is not only relevant to modelling nuclear fusion devices; it is also crucial in simulating the reaction that takes place on a spacecraft’s heat shield at the moment when it re-enters Earth’s atmosphere. Further, it can help us understand the physics and chemistry of planetary atmospheres. In a novel and comprehensive study just published in EPJ D, Masamitsu Hoshino from Sophia University, Tokyo, Japan, and colleagues reveal a method for controlling the likelihood that these reactions between electrons and hot molecules occur, by altering the degree of bending the linear molecules, modulated by reaching precisely defined temperatures.

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EPJ D Topical Review - 20 years of microplasma research: a status report

The field of microplasmas gained recognition as a well-defined area of research and applications within the larger field of plasma science and technology about 20 years ago. Since then, the level of activity in microplasma research and applications has continuously increased.

A new review article published in EPJ D provides a snapshot of the current state of microplasma research and applications. Given the rapid proliferation of microplasma-based applications, the authors focus primarily on the status of microplasma science and on current understanding of the physical principles that govern the formation and behaviour of microplasmas. They also address microplasma applications, limiting such discussion to examples where the application is closely tied to the plasma science. The article includes some key references to recent reviews, describing some of the diverse range of current and emerging applications.

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EPJ D Highlight - Anti-hydrogen origin revealed by collision simulation

Scientists studying the formation of antihydrogen ultimately hope to explain why there is more matter than antimatter in the universe. © vpardi / Fotolia

Numerical model takes us one step closer to understanding anti-hydrogen formation, to explain the prevalence of matter and antimatter in the universe

Antihydrogen is a particular kind of atom, made up of the antiparticle of an electron - a Positron - and the antiparticle of a Proton - an antiproton. Scientists hope that studying the formation of anti hydrogen will ultimately help explain why there is more matter than antimatter in the universe. In a new study published in EPJ D, Igor Bray and colleagues from Curtin University, Perth, Australia, demonstrate that the two different numerical calculation approaches they developed specifically to study collisions are in accordance. As such, their numerical approach could therefore be used to explain antihydrogen formation.

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EPJ D Highlight - Recipe for muon pair creation, in theory

State distributions for collision between negatively charged muons and muonic hydrogen atoms.

Creation of ephemeral muonium atoms could help measure proton size

A true-muonium only lives for two microseconds. These atoms are made up one positively and one negatively charged elementary particle, also known as muons. Although they have yet to be observed experimentally, a Japanese theoretical physicist has come up with new ways of creating them, in principle, via particle collisions. The first method involves colliding a negatively charged muon and a muonium atom made up of a positive muon and an electron. The second involves colliding a positively charged muon and a muonic hydrogen atom made up of a proton and a negative muon. The author found that the second option offers the most promising advances for muonium detection. These findings have been published in EPJ D by Kazuhiro Sakimoto from the Japan Aerospace Exploration Agency in Kanagawa.

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EPJ D Highlight - Minutest absolute magnetic field measurement

Geometry of the experiment.

High-precision and high-accuracy magnetic field measurement to support quest for missing antimatter in the universe

Every measurement is potentially prone to systematic error. The more sensitive the measurement method, the more important it is to make sure it is also accurate. This is key for example in measuring magnetic fields in state-of-the-art fundamental physics experiments. Now, an international team of physicists has developed an extremely high-precision method for the determination of magnetic fields. The resulting device, they found, has an intrinsic sensitivity that makes it ideal for fundamental physics and cosmology experiments attempting to explain the missing antimatter of the universe. The findings by Hans-Christian Koch from the University of Fribourg, Switzerland, and colleagues have just been published in EPJ D.

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EPJ D Highlight - Bringing the chaos in light sources under control

Experimental reconstruction of the phase portrait of the quantum dot light emitting diode using the embedding technique.

Study investigates how best to stabilise the output of quantum dot LEDs

Noise is an issue in optical telecommunications. And findings means of controlling noise is key to physicists investigating light-emitting diodes or lasers. Now, an Italo-Iraqi team has worked on a particular type of light source, called the quantum dot light-emitting diode (QDLED). In a study published in EPJ D, Kais Al Namee from the National Institute of Optics, in Florence, Italy and colleagues, demonstrate that modulating bias current of the QDLED could lead to countering the noise. This, in turn, leads to stabilising such light sources, making them better suited for optical telecommunications.

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EPJ D Highlight - New way of retaining quantum memories stored in light

Quantum information stored in photons can be preserved by confining light. © memorialphoto / Fotolia

Chinese scientists uncover a novel way of stopping light in a state that stores information encoded in photons, opening the door to applications in quantum information processing

A team of Chinese physicists has now developed a way to confine light. This is significant because the approach allows quantum memories stored within photons to be retained. These findings stem from a study by Nan Sun from Nanjing University of Posts & Telecommunications, China, and colleagues, which has just been published in EPJ D. The results may herald the advent of a multitude of hybrid, optoelectronic devices relying on the use of quantum information stored in photons for processing information that can be used in communication networks or quantum computing.

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Editors-in-Chief
V. Buzek, H. Kersten and A.V. Solov'yov
Thank you very much for processing this manuscript so rapidly, and obtaining two reports from competent referees.

Franck Laloë

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