2023 Impact factor 1.6
Condensed Matter and Complex Systems

News / Highlights / Colloquia

EPJ B Highlight - Ranking nanodevice functionality methods

A new paper links the deformation of molecules like benzene to charge transfer.

Examining the charge transfer influence of three charge control methods and producing a hierarchy promises important practical applications in nanodevices.

As the demand for nanodevices grows so too does the need to improve the functionality of such devices, which is vulnerable to changes in the charge distribution, energy levels or conformation. Hence the desire to assess the three current charge control methods: gating by electro-chemicals, doping by pendant groups and doping by annealed motifs.

A new paper published in EPJ B authored by Zainelabideen Yousif Mijbil, from the College of Science, Al-Qasim Green University, Al-Qasim Town, Babylon Province, Iraq, aims to prioritize and rank nano-device functionality methods according to their potential impact as well as justifying the reason for such an influence-based hierarchy.

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EPJ B Highlight - A novel computing approach to recognising chaos

An image showing portraits of chaos in systems with different set parameters.

Chaos isn’t always harmful to technology, in fact, it can have several useful applications if it can be detected and identified.

Chaos and its chaotic dynamics are prevalent throughout nature and through manufactured devices and technology. Though chaos is usually considered a negative, something to be removed from systems to ensure their optimal operation, there are circumstances in which chaos can be a benefit and can even have important applications. Hence a growing interest in the detection and classification of chaos in systems.

A new paper published in EPJ B authored by Dagobert Wenkack Liedji and Jimmi Hervé Talla Mbé of the Research unit of Condensed Matter, Electronics and Signal Processing, Department of Physics, University of Dschang, Cameroon, and Godpromesse Kenné, from Laboratoire d’ Automatique et d’Informatique Appliquée, Department of Electrical Engineering, IUT-FV Bandjoun, University of Dschang, Cameroon, proposes using the single nonlinear node delay-based reservoir computer to identify chaotic dynamics.

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EPJ B Highlight - Investigating newly synthesised thallium compounds for optoelectronic devices

A new research paper tests newly Synthesised Compounds for their suitability in Optoelectronic devices. Credit: Robert Lea

The burgeoning field of optoelectronic devices is driving the development of new alkali metal-based chalcogenides with qualities that have to be robustly investigated.

The need for efficient optoelectronic devices is growing and hand-in-hand so too is the challenge of discovering new semiconductors with valuable properties. This has spurred significant research in the synthesis and characterization of new alkali metal-based (AM) chalcogenides involving copper, silver and alkali metal with valuable properties like flexibility, high thermal stability, semiconductivity, photovoltaic effects.

Inspired by the growing demand for new optimum semiconducting materials, a new paper published in EPJ B authored by Abdelmadjid Bouhemadou, Laboratory for Developing New Materials and their Characterizations, Department of Physics, Faculty of Science, University of Ferhat Abbas Setif, Algeria and his co-authors, investigated in detail the structural, elastic, electronic and optical properties of two newly synthesized compounds, namely Tl2CdGeSe4 and Tl2CdSnSe4.

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EPJ B Colloquium - Ballistic annihilation in one dimension: a critical review

In a new Colloquium published in EPJB, S. Biswas (Universidad de Guadalajara, Mexico) and F. Leyvraz (Universidad Nacional Autónoma de México, Mexico) review several related systems. In the simplest, all particles move in a straight line at constant velocity in one dimension, and upon meeting, irreversibly react to an inert species. The simplest approach to such systems involves the “law of mass action” which leads, for large times, to a concentration decay of 1/t. The model described above for which all particles move with two possible distinct velocities only, has been solved exactly. In this case, it is shown that the concentration decay goes as t-1/2, so that the law of mass action is strongly violated.

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EPJ B Highlight - Understanding changes in a non-equilibrium economy

Capturing dynamics in the supply-demand curve

A novel theory can link abrupt, non-equilibrium changes to the state of the economy to a central principle of dynamics and thermodynamics

Equilibrium is a fundamental concept in economics: describing situations where the many interacting variables governing the state of the economy are static and perfectly balanced. Yet in reality, the inherent uncertainty and randomness associated with these variables, combined with the fragility of economists’ expectations, mean that the economy can never really be in true equilibrium. In new research published in EPJ B, a research team led by Kun Zhang from the Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences, and Jin Wang at State University of New York at Stony Brook, use new mathematical theories to capture the economy’s true non-equilibrium nature and to show how it can be quantified.

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EPJ B - New Editorial Board Member appointments

The Publishers and Editors-in-Chief of EPJB: Condensed Matter and Complex Systems are delighted to announce the appointment of three new members of the Editorial Board: Prof Veronica Barone of Central Michigan University, Mount Pleasant, USA; Prof Sanghamitra Neogiof the University of Colorado, Boulder, USA; and Dr Philipp Hövel (starting September 1st), of the School of Mathematical Sciences, University College Cork, Ireland.

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EPJ B Colloquium - Particles, conformal invariance and criticality in pure and disordered systems

Amplitude in the replicated q-state Potts model that becomes q-independent in the limit of n=0 replicas corresponding to quenched disorder. This provides the analytical mechanism able to explain the numerically observed superuniversality (i.e. symmetry-independence) of the correlation length critical exponent.

The two-dimensional case occupies a special position in the theory of critical phenomena due to the exact results provided by lattice solutions and, directly in the continuum, by the infinite-dimensional character of the conformal algebra. However, some sectors of the theory, and most notably criticality in systems with quenched disorder and short range interactions, have appeared out of reach of exact methods and lacked the insight coming from analytical solutions.

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EPJ B Highlight - Considering disorder and cooperative effects in photon escape rates from atomic gases

Photon escape rates in the case of scalar and vector fields for a cloud of N=700 atoms across a range of densities

Investigating more complex models of photon escape rates from cold atomic gases could help researchers learn more about light-matter interactions.

Whilst a great deal of research has studied the rates of photons escaping from cold atomic gases, these studies have used a scalar description of light leaving some of its properties untested. In a new paper published in EPJ B Louis Bellando, a post-doctoral researcher at LOMA, University of Bordeaux, France, and his coauthors—Aharon Gero and Eric Akkermans, Technion-Israel Institute of Technology, Israel, and Robin Kaiser, Université Côte d'Azur, France—aim to numerically investigative the roles of cooperative effects and disorder in photon escape rates from a cold atomic gas to construct a model that considers the vectorial nature of light. Thus, the study accounts for properties of light, previously neglected.

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EPJ B Highlight - Modelling the brain during pain processing

Building a realistic network

Novel approaches in graph theory have enabled researchers to reveal the characteristic configurations of neurons which arise as our brains process pain

The many different sensations our bodies experience are accompanied by deeply complex exchanges of information within the brain, and the feeling of pain is no exception. So far, research has shown how pain intensity can be directly related to specific patterns of oscillation in brain activity, which are altered by the activation and deactivation of the ‘interneurons’ connecting different regions of the brain. However, it remains unclear how the process is affected by ‘inhibitory’ interneurons, which prevent chemical messages from passing between these regions. Through new research published in EPJ B, researchers led by Fernando Montani at Instituto de Física La Plata, Argentina, show that inhibitory interneurons make up 20% of the circuitry in the brain required for pain processing.

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EPJ B Colloquium - Record dynamics of evolving metastable systems: theory and applications

Microscopically very different physical, biological and cultural systems all evolve through a sequence of stages, each characterized by stationary fluctuations around constant values of relevant macroscopic observables. Sudden and rapid changes, called quakes, induce transitions from one stage to the next and reveal the non-equilibrium nature of the dynamics. The duration of the stages increases over time, producing a multi-scaled dynamical behavior known in physics under the name of ``physical aging'', and rooted in all cases in a hierarchically structured underlying configuration space. Record Dynamics (RD) is a coarse-graining approach treating the staged evolution of complex metastable systems with the same statistical tools. This colloquium paper reviews RD methods and ideas that have gradually evolved over time and shows how RD can be applied to selected cases of biological and physical origin. The main property described is that quakes are a log-Poisson process and that the coarse-grained dynamics is therefore log-time homogeneous. The bibliography points the interested reader to the original RD papers and their background.

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Editors-in-Chief:
R. Egger and H. Rieger
I am naturally indebted to you and the referees who contributed to this success with your time and constructive advice.

Hamid Assadi

ISSN (Print Edition): 1434-6028
ISSN (Electronic Edition): 1434-6036

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