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arXiv · 2306.10637

Real-time observation of phonon-electron energy and angular momentum flow in laser-heated nickel

Vishal Shokeen·Michael Heber·Dmytro Kutnyakhov·Xiaocui Wang·Alexander Yaroslavtsev·Pablo Maldonado·Marco Berritta·Nils Wind·Lukas Wenthaus·Federico Pressacco·Chul-Hee Min·Matz Nissen·Sanjoy K. Mahatha·Siarhei Dziarzhytski·Peter M. Oppeneer·Kai Rossnagel·Hans-Joachim Elmers·Gerd Schönhense·Hermann A. Dürr
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Abstract

Identifying the microscopic nature of non-equilibrium energy transfer mechanisms among electronic, spin and lattice degrees of freedom is central for understanding ultrafast phenomena such as manipulating magnetism on the femtosecond timescale. Here we use time and angle-resolved photoemission spectroscopy to go beyond the often-employed ensemble-averaged view of non-equilibrium dynamics in terms of quasiparticle temperature evolutions. We show for ferromagnetic Ni that the non-equilibrium electron and spin dynamics display pronounced variations with electron momentum whereas the magnetic exchange interaction remains isotropic. This highlights the influence of lattice-mediated scattering processes and opens a pathway towards unraveling the still elusive microscopic mechanism of spin-lattice angular momentum transfer.

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Vishal Shokeen, Michael Heber, Dmytro Kutnyakhov, Xiaocui Wang, Alexander Yaroslavtsev, Pablo Maldonado, Marco Berritta, Nils Wind, Lukas Wenthaus, Federico Pressacco, Chul-Hee Min, Matz Nissen, Sanjoy K. Mahatha, Siarhei Dziarzhytski, Peter M. Oppeneer, Kai Rossnagel, Hans-Joachim Elmers, Gerd Schönhense, Hermann A. Dürr. 2023-06-18. Real-time observation of phonon-electron energy and angular momentum flow in laser-heated nickel. https://arxiv.org/abs/2306.10637

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