Ultrafast structural dynamics of the Fe-pnictide parent compound BaFe2As2

Abstract

Using femtosecond time-resolved x-ray diffraction we investigate the structural dynamics of the coherently excited A1g phonon mode in the Fe-pnictide parent compound BaFe2As2. The fluence dependent intensity oscillations of two specific Bragg reflections with distinctly different sensitivity to the pnictogen height in the compound allow us to quantify the coherent modifications of the Fe-As tetrahedra, indicating a transient increase of the Fe magnetic moments. By a comparison with time-resolved photoemission data we derive the electron-phonon deformation potential for this particular mode. The value of Delta mu/Delta z = -(1.0 - 1.5) eV/A is comparable with theoretical predictions and demonstrates the importance of this degree of freedom for the electron-phonon coupling in the Fe pnictides.

5 pages, 4 figures, Supplementary material

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Cited by in corpus (4)

• Direct measurement of electron-phonon coupling with time-resolved ARPES
• Direct characterization of photo-induced lattice dynamics in BaFe2As2
• First-principles modelling for time-resolved ARPES under different pump-probe conditions
• Electronic structure and ultrafast dynamics of FeAs-based superconductors by angle- and time-resolved photoemission spectroscopy