Dresden 2017 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 24: Low-Dimensional Systems: 1D - Theory
TT 24.6: Vortrag
Dienstag, 21. März 2017, 10:45–11:00, HSZ 204
Photoexcitations in a 1D manganite model: From quasiclassical light absorption to quasiparticle relaxations — •Thomas Köhler1, Sangeeta Rajpurohit2, Ole Schumann1, Fabian Biebl1, Mohsen Sotoudeh2, Stephan Kramer3,1, Peter Blöchl2,1, Stefan Kehrein1, and Salvatore Manmana1 — 1Inst. f. Theo. Phys., U. Göttingen — 2Inst. f. Theo. Phys., TU Clausthal — 3Fraunhofer ITWM Kaiserslautern
We investigate the dynamics of 1D correlated systems after photoexcitation by combining ab-initio methods, time-dependent matrix product states (MPS), linearized quantum Boltzmann equations (LBE), and molecular dynamics (MD) simulations. This leads to a description spanning a wide range of time scales from femto- up to nanoseconds. We consider manganite systems in the material class Pr1−xCax MnO3 for which we derive 1D ab-initio model Hamiltonians. At half doping, we obtain a magnetic microstructure of alternating dimers from which we derive a 1D Hubbard-type model. The dynamics is analyzed concerning the formation and lifetime of such quasiparticles via a LBE. We find that the magnetic microstructure strongly enhances the lifetime of the excitations. In this way, our work constitutes a first step to building a unifying theoretical framework for the description of photoexcitations in strongly correlated materials over a wide range of time scales, capable of making predictions for ongoing experiments investigating pump-probe situations and unconventional photovoltaics.
Financial support by DFG CRC1073 (projects B03 and C03) is gratefully acknowledged.