Ultrafast non-equilibrium magnon generation and collapse of spin-orbit hybridization gaps in iron

Xinwei Zheng; Shabnam Haque; Christian Strüber; Martin Weinelt

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arXiv · 2507.04875

Ultrafast non-equilibrium magnon generation and collapse of spin-orbit hybridization gaps in iron

Xinwei Zheng·Shabnam Haque·Christian Strüber·Martin Weinelt

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Abstract

We distinguish between longitudinal and transverse spin excitations in the ultrafast response of iron by probing exchange splitting {\Delta}Eex and magnetic linear dichroism (MLD) in time- and angleresolved photoemission. Comparing spin-split partner bands at the Fermi level shows that {\Delta}Eex remains constant upon optical excitation. In contrast, the different MLD response of spin-orbitsplit valence bands reveals non-equilibrium, transverse spin dynamics. Magnon generation in Fe is ultrafast, electronic band specific, and drives the collapse of spin-orbit hybridization gaps.

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Xinwei Zheng, Shabnam Haque, Christian Strüber, Martin Weinelt. 2025-07-07. Ultrafast non-equilibrium magnon generation and collapse of spin-orbit hybridization gaps in iron. https://arxiv.org/abs/2507.04875

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