Psi-k - Ab initio (from electronic structure) calculation of complex processes in materials

Ab-initio Methods for Correlated Spintronics Materials: Theories and Applications

Workshop on Ab-initio Methods for Correlated Spintronics Materials:
Theories and Applications

Monastery of Mont Sainte Odile, Strasbourg, France, September 4-7, 2004.

Coordinators:
M. Alouani (U. of Strasbourg),
S. Biermann (Ecole Polytech, Paris),
A. Lichtenstein (U. of Nijmegen)

Contact person:
M. Alouani (U. of Strasbourg)

Short Abstract

The workshop will bring together researchers who are using different methodologies for strongly correlated materials along with people from the band theory community who are interested in correlated materials. we propose to investigate the specific physical properties of many interesting materials, and compare them to what can be understood using the quantitative tools now under development. This should allow to paint a broader picture of the strong correlation problem, and to evaluate more accurately the current status of theoretical understanding. We propose also to ask some of the invited speakers to gather their contributions on a book which will be beneficial to graduate students and postdocs in order to understand existing numerical programs or to add new extensions. The book will be different from any existing book on the subject, since it will provide most of the computational details about the implementation of the these methods.

We propose a workshop in condensed matter physics which is motivated by recent advances in the treatment of electronic correlation effects, particularly in the context of realistic electronic structure calculations. The workshop will attempt to balance two important components: the development of new methods, and applications of these methods to experimentally relevant systems. The main objective is to gain new physical understanding into the working of complex materials.

Significant progress in the field of strongly correlated electrons has been achieved recently with the developments of dynamical mean-field theory (DMFT), and on the GW method both in studies of model systems and in combining it with realistic band-theory methods. There are already many indications that realistic implementations of DMFT and GW constitute a scientific opportunity to solve in a quantitative manner problems which have so far defied analysis with more traditional techniques, for example the Mott metal to insulator transition, itinerant ferromagnetism and the behavior of heavy fermions. Taking advantage of this opportunity requires bringing together experts in electronic structure, and many body theory. The DMFT and GW will be the central methods discussed in the workshop, because they have been extensively developed over the last ten years, and continue to be extended and improved.

We propose the following team to coordinate the workshop,
M. Alouani (U. of Strasbourg), contact person,
S. Biermann (Ecole Polytechnique, Paris),
A. Lichtenstein (U. of Nijmegen).

M. Alouani has been very active with his students to develop the GW approximation using an all electron method, the so called Projector Augmented Wave (PAW) method. S. Biermann together with A. George is responsible for many advancement of the dynamical mean-field approach, and is an active contributor to the general field of many body theory. A. Lichtenstein has been among the first to implement DMFT in a realistic setting (his work parallels the independent work of S. Biermann and the Ekaterinburg group. He has carried out many early investigations of transition metal oxides within DMFT.

Key proposed participants:

The workshop will be held in the monastery of Mont Sainte Odile, which is about 50 km from Strasbourg and its duration is from Saturday September 4th to Tuesday September 7th, 2004. The cost of a single room with fullboard is 65 euros per person. We propose to pay the local expenses for all invited speakers, and the travel expenses only to invited speakers from East Europe (Katsenelson, Kudonovsky), Japan (Aryasetiawan). We ask the Ψk network for 10000 euros.

The workshop will bring together researchers who are using different methodologies for strongly correlated materials along with people from the band theory community who are interested in correlated materials. This workshop will then set a new start for further developement in the theory of correlated materials. Furthermore, the workshop will be strongly oriented towards the discussion of a large number of specific materials of great current experimental interest. Sharing insights from diverse materials and different calculation methods should allow to distinguish between common aspects and non universal (material-specific) aspects, hence shedding light on what are the new physical principles that govern the behavior of strongly correlated materials. The basic issues raised (evolution from band behavior to atomic behavior in the presence of orbital degeneracy and multiplet structure, interaction of local moments and charge carriers) are very basic and general. However the approach taken in the present proposal is quite different. Rather than search for abstract unifying principles, we propose to investigate the specific physical properties of many interesting materials, and compare them to what can be understood using the quantitative tools now under development. This should allow to paint a broader picture of the strong correlation problem, and to evaluate more accurately the current status of theoretical understanding, a key step for further progress. We propose also to ask some of the invited speakers to gather their contributions on a book which will be beneficial to graduate students and postdocs in order to understand existing numerical programs and to add new extensions. The book will be different from any existing book on the subject, since it will provide most of the computational details about the implementation of these methods.