Regensburg 2013 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 69: Superconductivity: Fe-based Superconductors - Theory

TT 69.4: Talk

Friday, March 15, 2013, 10:30–10:45, H21

A1g phonon-induced electron dynamics of Fe pnictides at ultra-fast time scales — •Bhaskar Kamble and Ilya Eremin — Theoretical Physics III, Ruhr Universität Bochum, 44801 Bochum

We employ the five-orbital tight-binding model to study the A1g phonon-induced electron dynamics of the Fe pnictides in the context of recent tr-ARPES experiments on BaFe2As2. By analyzing the experimental data we deduce the amplitude of the tetrahedra angle oscillation due to the A1g phonon and the modified band structure topology. We also find that in order to account for the experimental data in the coherent regime, the oscillations of the electronic structure should occur simultaneously with oscillations of the charge density on the iron site and we evaluate the amplitude of these oscillations from the five orbital model. Finally, we analyze the change in the magnetization as a function of the tetrahedral angle and find it is not symmetric around the mean value. This results in a higher value of the average magnetization within a cycle of the A1g phonon compared to the magnetization at the average value of the tetrahedral angle. This suggests that coherent oscillation of the A1g phonon mode may induce transient generation of the SDW state, and also suggests that the interaction strength in the Fe pnictides lies in the weak to the intermediately coupled regimes.