Controlling magnetism and self-organization of adatoms on surfaces by using quantum interferences
Prof. Dr. P. Bruno (MPI für Mikrostrukturphysik, Halle)

Due to the presence of a surface state, a quasi-free two-dimensional electron gas (2DEG) floats on the (111) surface of noble metals. This 2DEG mediates long-range oscillatory interactions among adatoms, and therefore controls to a large extent the formation of magnetic nanostructures on such surfaces. The competition between this long-range inter-adatom interaction and the adatom-surface interaction gives rise to a wide variety of structures, depending on the nature of adatoms, on their density, on temperature, on the presence of atomic steps, etc.
These processes have been studied theoretically by using a combination of first-principles and kinetic Monte-Carlo methods. We have also investigated the spin-polarization and the exchange interaction among adatoms mediated by the 2DEG, as well as how they can be influenced by using quantum confinement and quantum interferences.

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