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Condensed Matter and Complex Systems

News / Highlights / Colloquia

In Memory of Prof Amit Dutta

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.

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EPJ B Topical Issue on Recent developments in the functional renormalization group approach to correlated electron systems

Guest editors: Carsten Honerkamp, Dante Kennes, Volker Meden, Michael Scherer and Ronny Thomale.

This Topical Issue of EPJ B brings together a collection of articles on the recent progress of the application of the functional renormalization group to correlated electron systems.

In condensed-matter physics strong correlations between electrons in materials and devices are responsible for the formation of many intriguing emergent phenomena, including various types of magnetism, (unconventional) superconductivity, Kondo-like effects or interaction-induced topological phases. Theoretical progress in the understanding of correlated electron systems requires the dedicated development of modern and powerful quantum many-body methods. One rather versatile method is the functional renormalization group, which has recently witnessed major methodological advances and extensions. This includes aspects of the renormalization group formulation, increased computer power and enhanced interlinks to ab initio quantum material methods, extensions to novel strongly correlated electronic models, and electronic systems out of equilibrium.

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EPJ B Highlight - Assessing the effect of hydraulic fracturing on microearthquakes

A cross-section of a hydrofracturing site showing preconditioning by blasting. Credit: de la Barra. E., et al, [2022]

New research examines mining sites with hydraulic fracturing comparing it to those without to determine the practice’s effect on seismic hazards.

The analysis of low-intensity human-caused microearthquakes, including their magnitude and frequency, has become an important factor in mining. This is a consideration not only for the safety of mining staff, but also for extraction rates and mine stability that can have major impacts on business performance. Increasingly, the practice of hydraulic fracturing is used to precondition mines and diminish the magnitude of induced tremors as well as reduce the number of rock fragments extracted.

A new paper published in EPJ B assesses the impact of hydraulic fracturing on seismic hazards like microearthquakes, an important issue for the safety of workers and the continuation of mining operations. The paper is authored by Erick de la Barra, Pedro Vega-Jorquera and Héctor Torres from the University of La Serena, Chile, alongside Sérgio Luiz E. F. da Silva from Politecnico di Torino, Department of Applied Science and Technology, Turin, Italy.

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EPJ B Highlight - Bringing consistency to methods of 2D material analysis

A sheet of 2D material-graphene-curved to create a nanotube. Credit: Michael Ströck (CC by SA 3.0)

New research introduces a more cohesive approach to the functional renormalization group — a key tool in the analysis of 2D materials

In materials science, the term “2D materials” refers to crystalline solids that consist of a single layer of atoms, with arguably the most famous example being graphene — a material made of a single layer of carbon atoms. These materials are promising for a wide range of applications including in sophisticated electronics and quantum computing thanks to their unique quantum properties.

One of the most promising methods of investigating these materials, and specifically their temperature instabilities, and for investigating quantum many-body phenomena is the functional renormalisation group (FRG). Yet, despite significant efforts, no systematic and comprehensive cohesion exists for different momentum space FRG implementations.

A new paper published in EPJ B and authored by Jacob Beyer, Institute for Theoretical Solid State Physics, RWTH Aachen University, Germany, alongside Jonas B. Hauck, and Lennart Klebl of the university’s Institute for Theory of Statistical Physics lays out a potential groundwork for achieving consistency across FRG methods.

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EPJ B Highlight - Studying the pseudogap in superconducting cuprate materials

The evolution of the Fermi surface showing under low doping pseudogap remains open, though pocket regions rich in holes start to form around the centre of the sBZ boundary

Despite being vital to the study of superconductivity in cuprate materials the physical origins of the pseudogap remain a mystery.

Over three decades since the discovery of high-temperature superconductivity in ceramic cuprate materials, investigating the electronic states in cuprate materials to advance the understanding of the superconducting phase and related phenomena has become of incredible importance.

In a new paper published in the EPJ B, Ernesto Raposo from the Federal University of Pernambuco, Brazil, and his co-authors, look at one of the essential physical properties of cuprate superconducting compounds, the pseudogap, which describes a state where the Fermi surface of a material possesses a partial energy gap.

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EPJ B Highlight - Thin quantum wires work better with less insulating coatings

Insulating effects of confined vs unconfined electrons

New theoretical analysis considers cases where the electrons are allowed to exist beyond the boundaries of semiconducting quantum wires – with important implications for their performance.

Thin, semiconducting wires have attracted much recent attention in physics – both in experiments and theoretical analysis. Named ‘quantum wires,’ these structures are often coated in insulating materials, and several previous studies have now explored how the mismatch between the insulating properties of both materials can influence their performance. Through new analysis published in EPJ B, Nguyen Nhu Dat and Nguyen Thi Thuc Hien at Duy Tan University, Vietnam, show that thinner wires with less insulating coatings can improve the mobility of the electrons they carry.

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EPJ B Highlight - Simulating realistic lane changes in two-lane traffic

Quantifying lane-changing rates.

A new approach to simulating traffic considers how drivers will change lanes at different rates depending on the density of traffic surrounding them

Many urban areas worldwide are now rapidly expanding, often with major negative impacts on traffic congestion. To address this issue, researchers have constructed models aiming to simulate the flow of traffic – but so far, they haven’t widely considered the impacts of drivers changing lanes. In a new study published in EPJ B, Nikita Madaan and Sapna Sharma at the Thapar Institute of Engineering and Technology, India, show how the lane-changing behaviours observed in real drivers can be incorporated into simulations of two-lane roads.

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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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Editors-in-Chief:
E. Hernandez and H. Rieger
Thank you for the very fruitful and efficient collaboration. It has been a pleasure!!

Paul van Loosdrecht, Guest Editor Topical issue: Excitonic Processes in Condensed Matter, Nanostructured and Molecular Materials, 2013

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

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