Rotter, D. (2011). Double exchange model for manganite clusters [Diploma Thesis, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/161168
We present model calculations for nanoscopic systems including Hund's coupling with localized, classical spins. We compare the results of the recently introduced nanoscopic version of the dynamical vertex approximation (nano-D[Gamma]A) at dynamical mean field level against an exact solution for a Benzene-like ring, where the latter is doable. This comparison allows us to investigate the reliability of the approximation. It shows that, already at the simplest approximation level (i.e. including only local correlations) the nano-D[Gamma]A results are very accurate in a rather wide range of parameters. Since the computational effort is highly reduced, it is suitable for studying more complex systems.
