Berlin 2015 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: POSTER Ia

MA 19.4: Poster

Dienstag, 17. März 2015, 09:30–13:00, Poster A

Polaron dynamics and evolution of polaronic microstructure in manganites — •Sangeeta Rajpurohit¹ and Peter Blöchl^1,2 — ¹Institute of Theoretical Physics, Clausthal Institute of Technology — ²Institute of Material Physics, University of Göttingen

Mixed-valence manganites exhibit interesting transport properties because of their complex interplay between charge, orbital, lattice and spin degrees of freedom. Strong electron-phonon coupling due to Jahn-Teller distortion localizes the electrons in the e_g states as polarons. These polarons dictate the charge transport, structural and magnetic ordering properties of manganites. We investigate the dynamics on long length and time scales with Car-Parinello molecular dynamics for a model Hamiltonian. The model Hamiltonian takes into account the electrons in the e_g orbitals of Mn, the classical spin of the t_2g electrons on Mn and the cooperative Jahn-Teller distortions of the oxygen octahedra. The electrons are treated as two-component spinors, allowing for non-collinear spin arrangements. So far, we explored the complex phase diagram of one-dimensional model manganites as function of the model parameters. These studies provide guidance for the study of the dynamics and the microstructure evolution of realistic two and three dimensional manganates. The parameters used in the model will be extracted from Density Functional Theory using hybrid functionals.

The work has been supported by the DFG through SFB 1073 B03.