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arXiv · 1610.07246

Relaxation of photoexcitations in polaron-induced magnetic microstructures

Thomas Köhler·Sangeeta Rajpurohit·Ole Schumann·Sebastian Paeckel·Fabian R. A. Biebl·Mohsen Sotoudeh·Stephan C. Kramer·Peter E. Blöchl·Stefan Kehrein·Salvatore R. Manmana
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Abstract

We investigate the evolution of a photoexcitation in correlated materials over a wide range of time scales. The system studied is a one-dimensional model of a manganite with correlated electron, spin, orbital, and lattice degrees of freedom, which we relate to the three-dimensional material Pr$_{1-x}$Ca$_{x}$MnO$_3$. The ground-state phases for the entire composition range are determined and rationalized by a coarse-grained polaron model. At half-doping a pattern of antiferromagnetically coupled Zener polarons is realized. Using time-dependent density-matrix renormalization group (tDMRG), we treat the electronic quantum dynamics following the excitation. The emergence of quasiparticles is addressed, and the relaxation of the nonequilibrium quasiparticle distribution is investigated via a linearized quantum-Boltzmann equation. Our approach shows that the magnetic microstructure caused by the Zener polarons leads to an increase of the relaxation times of the excitation.

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Thomas Köhler, Sangeeta Rajpurohit, Ole Schumann, Sebastian Paeckel, Fabian R. A. Biebl, Mohsen Sotoudeh, Stephan C. Kramer, Peter E. Blöchl, Stefan Kehrein, Salvatore R. Manmana. 2018-06-12. Relaxation of photoexcitations in polaron-induced magnetic microstructures. https://doi.org/10.1103/physrevb.97.235120

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