A: Solid State and Materials Lattice structure and dynamics Inhomogeneous and disordered systems Glasses and amorphous materials Quantum solids and liquids Electronic structure and dynamics Low-dimensional systems Topological insulators and superconductors Graphene and related materials Strongly correlated electron systems Cold atoms and quantum simulators Surfaces and interfaces Thin films, multilayers and superlattices Semiconductors Magnetic structure and dynamics Random magnetism and frustrated magnets Quantum spin systems Spin-dependent transport Spintronics Superconductivity B: Mesoscopic and Nanoscale Systems Clusters and nanotubes Quantum dots and wires Quantum coherence Nanoelectronics Optoelectronics Nanomechanics C: Computational Methods Ab-initio methods Classical and quantum many-body schemes Atomistic simulations Multi-scale modeling Kinetic algorithms Lattice-Boltzmann methods Cellular automata and agent-based modeling D: Statistical and Nonlinear Physics Equilibrium statistical mechanics and thermodynamics Non-equilibrium statistical mechanics Information theory approaches and complexity measures Phase transitions and critical phenomena Fluctuation phenomena and stochastic processes Chaos and nonlinear dynamical systems Collective dynamics and self-organization Science of networks Interdisciplinary theory, modeling and applications Article Categories Regular Articles Colloquia Topical Reviews Colloquia describe the development of new areas of research or the impact of new and promising experimental or theoretical methods in the fields that are within the spectrum of topics covered by the respective journals. While not as extensive and complete as reviews in the usual sense, they are intended to suitably introduce new research directions and techniques in their early stages of development, and to a wider audience. There is no explicit constraint regarding the length of such manuscripts, although 20 printed pages would be the most usual length. All invited/submitted manuscripts will undergo the same refereeing procedure as all other contributions submitted to the journal. For invited colloquium papers, authors will receive a honorarium of EUR 400,-- upon publication and colour figures will be free of charge. Colloquium papers are generally solicited by the journal editors. Authors wishing to submit a colloquium paper are advised to contact the Editors-in-Chief. Topical Reviews provide a comprehensive and extensive summary of recent research results in a field that is within the spectrum of topics covered by EPJ B and are of current interest to a broader audience. A topical review should aim to summarize the pertinent experimental, theoretical, and computational results obtained by the key research groups working in the field in the past 10 years. Historical reviews of an entire sub-field of physics are discouraged. There is no explicit constraint regarding the length of such manuscripts, although 35 printed pages would be the most usual length. All invited/submitted manuscripts will undergo the same refereeing procedure as all other contributions submitted to the journal. For invited topical review papers, authors will receive a honorarium of EUR 400,-- upon publication and color figures will be free of charge. Topical review papers are generally solicited by the journal editors. Authors wishing to submit a topical review paper are advised to contact the Editors-in-Chief. .