EPJ

Open Calls for Papers

EPJ B Topical Issue : Phase Transitions and Magnetism in Spin Systems

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Published on 27 March 2025

Guest Editors: Erol Vatansever, Edson Vernek and Volker Meden

Submissions are invited for a Topical Issue of EPJ B on Phase Transitions and Magnetism in Spin Systems.

Research on the magnetic properties of spin systems is a cornerstone of modern condensed matter physics, offering profound insights into the behavior of quantum matter. This field explores how interactions, dimensionality, and quantum fluctuations give rise to diverse magnetic phases and phase transitions. Key models, given by the Heisenberg and Hubbard many-body Hamiltonians, provide frameworks to understand phenomena like geometric frustration, competing interactions, and the emergence of exotic quantum states of matter, including quantum spin liquids, valence bond solids, and topological phases. These states challenge classical notions of magnetism, underscoring the pivotal role of quantum mechanics in shaping material properties.

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EPJ B Topical Issue: High Field Superconducting Magnets: Materials, Technology and Applications

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Published on 19 December 2024

Guest Editors: Jinxing Zheng, Yoshikazu Mizuguchi, Jianhua Liu, Ivan Shorubalko

Submissions are invited for a Topical Issue of EPJ B on High Field Superconducting Magnets: Materials, Technology and Applications.

With the continuous development of superconducting materials and superconducting magnet technology, it has played an increasingly important role in power systems, medical equipment, fusion devices and other fields. The superconducting power transmission can save a lot of energy loss. Superconducting medical devices (such as MRI, proton therapy devices and so on) offer a powerful path to better disease diagnosis and improved treatment outcomes. The construction of magnetic confinement fusion devices is also based on high-field superconducting magnets. The core issue of the superconducting technology is to maintain superconducting state under different operation conditions. To address this issue, many superconducting physics problems are analyzed and studied from a systematic perspective, such as superconducting materials, critical performance, AC loss calculation, stability margin, quench propagation etc. The critical performance will affect the AC loss and stability evaluation. None of these challenges can be addressed in isolation. The research of superconducting technology is a complex system engineering.

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EPJ B Topical Issue : CompLex: Complexity Science for Legal Applications

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Published on 14 November 2024

Guest Editors: Pierpaolo Vivo, Daniel Martin Katz, J.B. Ruhl, Philipp Hövel

Submissions are invited for a Topical Issue of EPJ B on CompLex: Complexity Science for Legal Applications.

In recent years, the intersection of law, governance, and complexity science has emerged as a fascinating and important area of study (See CompLex: legal systems through the lens of complexity science for a recent review).
Modern societies are regulated by intricate legal and governance systems that share many characteristics with complex adaptive systems traditionally studied in physics and mathematics. These include nonlinear effects, feedback loops, and emergent behaviors. As our world becomes increasingly interconnected and complex, there is a growing need to apply rigorous quantitative methods to analyze and improve our legal and governance frameworks.
The study of social institutions and governance has historically been confined to philosophy and social sciences. However, interdisciplinary applications of physics and other hard sciences have had a profound impact on our understanding of complex systems in biology, economics, and other fields. It is now time to extend this approach to law and governance.
For over a decade, complexity scientists have been turning their attention to societal issues, but it is only recently that important legal and political questions have been formulated in a language that science can comprehend and meaningfully address. While some barriers still exist, the time is ripe for a full-fledged cross-fertilization between law/governance, physics, and computer science.

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EPJ B Topical Issue: 100 Glorious Years of the Ising Model

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Published on 12 September 2024

Guest Editors: Muktish Acharyya, Yurij Holovatch, Ferenc Iglói

Submissions are invited for a Topical Issue of EPJ B on 100 Glorious Years of the Ising Model.

The Ising model was initially proposed by Wilhelm Lenz to Ernst Ising mainly to explain ferromagnetism. Ernst Ising solved the one-dimensional problem in his Doctoral thesis in 1924 and published in 1925, showing the absence of ferromagnetism. Lars Onsager found the exact solution of the two-dimensional model in 1944 showing the presence of spontaneous ferromagnetic order and ferromagnetic phase transition. Since then, the simplest discrete symmetric model (Ising model) for ferromagnets started to draw attention among researchers. Theoretical statistical physicists started to realize that this was not merely a model for ferromagnets, but that the Ising model could grasp many essential features of quantum tunneling effects in presence of a transverse field. The quantum phases of the transverse Ising model play an important role in modern research as well as the nonequilibrium phase transition with the kinetic Ising model. Later, this simple Ising model has been widely applied to study many complex phenomena beyond physics, like the dynamics of opinion formation and consensus. The importance of the Ising model has been demonstrated times and times again over the last 100 years. The aim of this focused issue is to collect original research articles, mini-reviews and pedagogical introductions that report recent advances related to the Ising model, its applications and its importance to modern physics.

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