News
EPJ E Highlight - Shear ultrasound shaking lowers friction between solids
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- Published on 15 February 2023
A simple new experiment shows how tiny ultrasound shaking at the interfaces between two objects will lower the friction between them – and in some cases, can induce sudden, large jerky motions
When high-frequency shaking occurs at an interface between two solids, recent experiments have revealed that the frictional forces between the objects can be weakened. Through a simple new experiment detailed in EPJ E, Julien Léopoldès at Université Gustave Eiffel, Marne la Vallée (formerly at ESPCI Paris) has discovered that mechanical vibrations also enhance structural aging in these systems, and can sometimes trigger sudden, jerking motions. The results could lead to a better understanding of how buildings are weakened by ambient vibrations, and may also help geologists to draw new insights into the mechanisms responsible for triggering earthquakes and landslides.
EPJA Topical Collection: CompOSE: a repository for Neutron Star Equations of State and Transport Properties
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- Published on 14 February 2023
Guest Editors: Danai Antonopoulou, Enrico Bozzo, Chikako Ishizuka, Ian Jones, Micaela Oertel, Constança Providencia, Laura Tolos and Stefan Typel
The CompOSE Topical Collection is a compendium of several works on neutron star equations of state (EoS) and transport properties related to the online repository CompOSE (CompStar Online Supernovae Equations of State).
EPJ D Highlight - Atoms slow down more within colder blackbody radiation
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- Published on 10 February 2023
New analysis shows that atoms will encounter high frictional forces in the presence of blackbody radiation at lower temperatures. Accounting for this effect could help researchers to improve the accuracy of high-precision experiments.
Blackbody radiation (BBR) contains electromagnetic waves with characteristic spectra, which changes shape depending on the temperature of the body. When moving atoms encounter these fields, they experience a repulsive force which slows down their movement towards the source of the radiation. Through new analysis published in EPJ D, Vipul Badhan and colleagues at Guru Nanak Dev University, India, show that the influence of this ‘blackbody friction force’ (BBFF) is particularly strong at lower temperatures.
EPJ H Highlight - Quarks and gluons: The JADE experiment at DESY
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- Published on 10 February 2023
A new paper in EPJ H describes the JADE experiment at DESY in Hamburg, in which high-energy electron-positron collisions led to the discovery of the particle that holds quarks together to form protons and neutrons: the gluon.
The DESY research centre in Hamburg has been at the centre of German physical science research since the 1960s, leading to important discoveries about the fundamental structure of matter. One experiment at DESY, known as JADE, recorded data on electron-positron collisions between 1979 and 1986. Siggi Bethke from the Max Planck Institute of Physics in Munich and Albrecht Wagner from DESY have now reviewed the history of JADE in the journal EPJ H: Historical Perspectives on Contemporary Physics.
EPJ B Highlight - Finely-tuned quantum dots enhance nonlinear optics
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- Published on 10 February 2023
Quantum dots with finely-tuned spherical defects could display advanced ‘nonlinear’ optical properties, new calculations have suggested. Adjusting the sizes of these defects could enable researchers to tightly control the brightness and frequency of the light they produce when illuminated.
Quantum dots are semiconductor particles measuring just a few nanometres across, which are now widely studied for their intriguing electrical and optical properties. Through new research published in EPJ B, Kobra Hasanirokh at Azarbaijan Shahid Madani University in Iran, together with Luay Hashem Abbud at Al-Mustaqbal University College, Iraq, show how quantum dots containing spherical defects can significantly enhance their nonlinear optical properties. By fine-tuning these defects, researchers could tightly control the frequency and brightness of the light emitted by quantum dots.
EPJ H Highlight - Mid-twentieth-century physics in the home of Galileo
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- Published on 10 February 2023
Breakthroughs made at the Institute of Physics near Florence before 1950 include Fermi statistics and the first electronic coincidence circuits
Florence was a flourishing centre for fundamental physics research throughout most of the twentieth century. Roberto Casalbuoni, Daniele Dominici and Massimo Mazzoni – all physicists currently working there – have reviewed the history of the city’s Institute of Physics for the journal EPJ H: Historical Perspectives on Contemporary Physics, concentrating on the important decades of the 1920s to 1960s.
EPJ D Topical review - Theory and molecular simulations of plasma sputtering, transport and deposition processes
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- Published on 03 February 2023
A new Topical Review published in EPJD provides an overview of the basic theory of sputtering with recent models, focussing in particular on sputtered atom energy distribution functions. Models such as Monte-Carlo, kinetic Monte-Carlo, and classical Molecular Dynamics simulations are presented due to their ability to describe the various processes involved in sputtering, transport and deposition processes.
EPJ E Highlight - Machine learning could help kites and gliders to harvest wind energy
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- Published on 02 February 2023
Using trial-and-error, machine learning algorithms could enable flying wind harvesters to dynamically adjust their orientations, allowing them to account for unpredictable turbulence and improve their performances.
Airborne wind energy (AWE) is a lightweight technology which uses flying devices including kites and gliders to harvest power from the atmosphere. To maximise the energy they extract, these devices need to precisely control their orientations to account for turbulence in Earth’s atmosphere. Through new research published in EPJ E, Antonio Celani and colleagues at the Abdus Salam International Center for Theoretical Physics, Italy, demonstrate how a Reinforcement Learning algorithm could significantly boost the ability of AWE devices to account for turbulence.
EPJ A Topical Collection: Light Clusters in Nuclei and Nuclear Matter: Nuclear Structure and Decay, Heavy Ion Collisions, and Astrophysics
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- Published on 02 February 2023
Guest Editors: David Blaschke, Hisashi Horiuchi, Masaaki Kimura, Gerd Röpke and Peter Schuck
Clustering in nuclei and nuclear matter is an interesting aspect which was intensely worked out during the last two decades. It concerns not only exotic nuclei such as Hoyle-like states, but leads to a better description of general aspects of nuclear structure and reactions. In particular, clustering is essential to understand fission and alpha decay, as well as heavy ion collisions from low to highest energies. In astrophysics, the thermodynamic properties of stellar matter below saturation density, transport properties, and the evolution of compact stellar objects are determined by clustering of nuclear matter. Contributions of this emerging field are collected in this Topical Collection.
In Memory of Prof Amit Dutta
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- Published on 27 January 2023
It is with great sadness that we learn of the sudden passing of Professor Amit Dutta (Indian Institute of Technology, Kanpur, India), member of the Editorial Board of EPJB. An elected Fellow of the Indian Academy of Sciences, Bengaluru, Prof Dutta was a member of the Physics Department at IIT Kanpur since 2003, having obtained his PhD from Jadavpur University in 2000. He was a post-doctoral fellow at the Max-Plank-Institut fur Physik Komplexer Systeme, Dresden and the Institut fur Theoretishe Physik, Universitat Wurzburg, and his research interests were in the fields of quantum phase transitions, non-equilibrium dynamics of quantum many body systems and quantum information.
