Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 48: Poster Session II

MA 48.58: Poster

Donnerstag, 10. März 2016, 15:00–18:00, Poster B1

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-Parrinello 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 have explored the complex phase diagram of one-dimensional model and three-dimensional manganites as function of the model parameters and doping. We observe dimer and trimer phases for different doping. We investigate the charge transport across the hetero interface of different polaronic behaviour. The parameters used in the model are extracted from Density Functional Theory using hybrid functionals.Financial support by the DFG Collaborative Research Center 1073 "Atomic scale control of energy conversion", project B03 is gratefully acknowledged.