PROJECTS

Relativistic Optimized Potential Method for magnetic solids

PRINCIPAL INVESTIGATOR

PROJECT RESEARCH ASSISTANT

ABSTRACT

The spin-polarized relativistic version of the optimized potential method (ROPM) could be successfully formulated and implemented. On the basis of the results for open-shell atoms and the developments made, investigations will be done for magnetic solids. With exchange treated on an exact exchange (EEX) level and correlations using the random phase approximation (RPA), these aim among other things to reveal the implications of weak points of the widely used local spin density approximation (LSDA). For this purpose investigations will be done on representative magnetic transition metal systems, calculating properties especially sensitive to exchange and correlation. These will be complemented by work on semiconductors focussing on the influence of spin-orbit coupling on the band gap. The ROPM-based studies will also supply a valuable reference for corresponding LSDA+DMFT (dynamical mean-field theory) investigations. This approach will also be applied to diluted magnetic semiconductors (DMS), that are a big challenge for ab-initio methods because of pronounced correlation effects. First steps to go beyond the single-site approximation used so far for the LSDA+DMFT could already been done by implementing the DMFT+Σ_k scheme. This will be used for photo emission calculations for high T_c -superconducting materials. As an alternative, an implementation of the cluster version of the LSDA+DMFT is planned.