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arXiv · 2210.13162

The interplay of local electron correlations and ultrafast spin dynamics in fcc Ni

Tobias Lojewski·Mohamed F. Elhanoty·Loïc Le Guyader·Oscar Grånäs·Naman Agarwal·Christine Boeglin·Robert Carley·Andrea Castoldi·Christian David·Carsten Deiter·Florian Döring·Robin Y. Engel·Florian Erdinger·Hans Fangohr·Carlo Fiorini·Peter Fischer·Natalia Gerasimova·Rafael Gort·Frank de Groot·Karsten Hansen·Steffen Hauf·David Hickin·Manuel Izquierdo·Benjamin E. Van Kuiken·Yaroslav Kvashnin·Charles-Henri Lambert·David Lomidze·Stefano Maffessanti·Laurent Mercadier·Giuseppe Mercurio·Piter S. Miedema·Katharina Ollefs·Matthias Pace·Matteo Porro·Javad Rezvani·Benedikt Rösner·Nico Rothenbach·Andrey Samartsev·Andreas Scherz·Justina Schlappa·Christian Stamm·Martin Teichmann·Patrik Thunstrom·Monica Turcato·Alexander Yaroslavtsev·Jun Zhu·Martin Beye·Heiko Wende·Uwe Bovensiepen·Olle Eriksson·Andrea Eschenlohr
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Abstract

The complex electronic structure of metallic ferromagnets is determined by a balance between exchange interaction, electron hopping leading to band formation, and local Coulomb repulsion. The interplay between the respective terms of the Hamiltonian is of fundamental interest, since it produces most, if not all, of the exotic phenomena observed in the solid state. By combining high energy and temporal resolution in femtosecond time-resolved X-ray absorption spectroscopy with ab initio time-dependent density functional theory we analyze the electronic structure in fcc Ni on the time scale of these interactions in a pump-probe experiment. We distinguish transient broadening and energy shifts in the absorption spectra, which we demonstrate to be caused by electron repopulation and correlation-induced modifications of the electronic structure, respectively. Importantly, the theoretical description of this experimental result hence requires to take the local Coulomb interaction into account, revealing a temporal interplay between band formation, exchange interaction, and Coulomb repulsion.

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Tobias Lojewski, Mohamed F. Elhanoty, Loïc Le Guyader, Oscar Grånäs, Naman Agarwal, Christine Boeglin, Robert Carley, Andrea Castoldi, Christian David, Carsten Deiter, Florian Döring, Robin Y. Engel, Florian Erdinger, Hans Fangohr, Carlo Fiorini, Peter Fischer, Natalia Gerasimova, Rafael Gort, Frank de Groot, Karsten Hansen, Steffen Hauf, David Hickin, Manuel Izquierdo, Benjamin E. Van Kuiken, Yaroslav Kvashnin, Charles-Henri Lambert, David Lomidze, Stefano Maffessanti, Laurent Mercadier, Giuseppe Mercurio, Piter S. Miedema, Katharina Ollefs, Matthias Pace, Matteo Porro, Javad Rezvani, Benedikt Rösner, Nico Rothenbach, Andrey Samartsev, Andreas Scherz, Justina Schlappa, Christian Stamm, Martin Teichmann, Patrik Thunstrom, Monica Turcato, Alexander Yaroslavtsev, Jun Zhu, Martin Beye, Heiko Wende, Uwe Bovensiepen, Olle Eriksson, Andrea Eschenlohr. 2022-10-24. The interplay of local electron correlations and ultrafast spin dynamics in fcc Ni. https://doi.org/10.1080/21663831.2023.2210606

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