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arXiv · 2310.19667

Dynamical renormalization of the magnetic excitation spectrum via high-momentum nonlinear magnonics

Christoph Schoenfeld·Lennart Feuerer·Julian Bär·Lukas Dörfelt·Maik Kerstingskötter·Tobias Dannegger·Dennis Wuhrer·Wolfgang Belzig·Uli Nowak·Alfred Leitenstorfer·Dominik Juraschek·Davide Bossini
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Abstract

Controlling macroscopic properties of quantum materials requires the ability to induce and manipulate excited states. The set of collective excitations of a solid is encoded in its dispersion relations. We find that the spectra of the low-momentum eigenmodes are renormalized by resonantly driving the high-momentum excitations. Our experimental data rule out laser-induced thermal processes as an origin of the renormalization. The photoinduced changes of the amplitudes and frequencies can be explained theoretically and numerically with a resonant light-scattering mechanism that couples high- and low-momentum eigenmodes in the dispersion relation across momentum space. While we demonstrate the renormalization of the magnetic spectrum in a quantum material, our experimental approach can be further generalized to lattice modes in semiconductors.

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Christoph Schoenfeld, Lennart Feuerer, Julian Bär, Lukas Dörfelt, Maik Kerstingskötter, Tobias Dannegger, Dennis Wuhrer, Wolfgang Belzig, Uli Nowak, Alfred Leitenstorfer, Dominik Juraschek, Davide Bossini. 2023-10-30. Dynamical renormalization of the magnetic excitation spectrum via high-momentum nonlinear magnonics. https://arxiv.org/abs/2310.19667

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