Working Group 10 - f-electron systems
Axel Svane, U Aarhus, Denmark
The magnetism of f-electron systems has been the subject of numerous studies in the past. Still, this topic remains a challenge with several unresolved issues. For example, many Ce-based materials exhibit complex magnetic structures at low temperature, with various exchange interactions competing with crystal field interactions, spin fluctuations and Kondo spin screening. As another example one could mention the extremely rich phase diagram of elemental Pu, with 11 different allotropes, which till now has not been properly understood. Finally, magnetism at surfaces, due to the lower coordination, is completely different from bulk magnetism, and of the utmost importance for understanding various spectroscopies as well as magnetic devices.
At the heart of the matter is the intricate quantum mechanical nature of the f-electron. Depending on the chemical surroundings, temperature, applied magnetic field and/or pressure, the f-electrons can vary from being essentially atomic-like, i.e., localized to a particular site, to being essentially band-like, i. e., spreading their wavefunction out over the entire system. Present day electronic structure methods are capable of describing both of these extreme situations, with the band-picture being implemented in the local-density approximation, while the localized picture can be invoked either by applying self-interaction corrections or by introducing an extra Hubbard U-term in the Hamiltonian. Real materials most often lie in between these extremes. An emerging activity in these years aims at bridging the gap between the above extremes of f-electron behavior. The aim is to combine the accuracy of ab-initio methods with a proper many-body treatment of the f-electrons. A promising way is the dynamical mean field theory, which incorporates the important aspect of the dynamical fluctuations of the f-electron manifold. Several of the groups of the present Network are key contributors to this development, which in a few years will lead to substantial progress in materials specific studies of the complex magnetic behavior in lanthanides and actinides.
MEMBERS OF THE WORKING GROUP [9 members + 7 others interested]
- A. Svane (
),
Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus, Denmark - B. Johansson, Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, SE-100 44, Stockholm, Sweden
- H. Eschrig, Department of Theoretical Solid State Physics, IFW Dresden e.V., P.O. Box 270016, D-01171 Dresden, Germany
- P. Strange, School of Chemistry and Physics, Keele University, Keele, Staffordshire, ST5 5BG, United Kingdom
- M. S. S. Brooks, European Commission Joint Research Center, Institute for Transuranium Elements, D-76125 Karlsruhe, Germany
- A. Georges, Laboratoire de Physique Théorique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
- H. Winter, INFP, Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe, Germany
- A. I. Lichtenstein, University of Nijmegen, Toernooiveld 1, NL-6525 ED Nijmegen, The Netherlands
- W. M. Temmerman, Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom
OTHERS INTERESTED
- O. Eriksson, Condensed Matter Theory Group, Uppsala University, Box 530, 751 21 Uppsala, Sweden
- H. Ebert, Department Chemie-Physikalische Chemie, Universität München, Butenandtstrasse 5-13, D-81377 München, Germany
- B. L. Gyorffy, H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8-1TL, United Kingdom
- Julie B. Staunton, Department of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
- J. Hafner, Institut für Materialphysik and Center for Computational Materials Science, Universität Wien, Sensengasse 8/12, A-1090 Wien, Austria
- W. Wolf, Institut für Physikalische Chemie, Universität Wien, Liechtensteinstrasse 22A, A-1090 Vienna, Austria
- J. Kuebler, Institut für Festkörperphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany