The activities of the Max Planck Fellow Group started in 2OO7. We do basic research in the field of solid state theory. We are interested in a material-specific and parameter-free description of nanostructured systems. Our research is based on density functional theory formulated in terms of Green functions. Green functions are very powerful for the consideration of systems with arbitrary geometry like heterostructures, thin films, surfaces, adatoms on surfaces or nanocontacts. The numerical effort of our method scales with the number of atoms. In this respect we are able to treat nanostructures of realistic size.
Our investigations start from the atomic structure of a system which is either known from experiment or can be determined numerically by structural relaxation. The main focus of our work is the microscopic understanding of the electronic, magnetic, ferroelectric, and transport properties on the atomic scale.
A substantial part of our research is dedicated to the emerging field of spintronics. Spintronics has a large potential for future applications in sensor and information technology in which the charge and spin-degree of freedom of the electrons are exploited. A successful application requires achieving control of the materials and processes involved on the atomic scale. To support the experimental developments, to predict new materials and to optimize the effects, first-principles electronic structure calculations based on density functional theory are the method of choice. Our method is applied to gain insight into the microscopic origin of spin-dependent transport of magnetic heterostructures as well as metallic and molecular contacts. The basic effects of spintronics like giant magnetoresistance (GMR) and tunneling magnetoresistance (TMR) have been investigated. Charge and heat to spin current conversion by means of the spin Hall effect (SHE) and the spin Nernst effect (SNE) as well as magnetoelectric coupling via multiferroic interfaces are currently focus areas of our research.
Our activities are embedded in the Collaborative Research Centre 762: Functionality of Oxide Interfaces. Here we investigate metal-oxide and oxide-oxide interfaces. Their atomic structure is the key for the resulting electronic and functional properties. Based on our calculations we design new materials with optimized functionalities.