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arXiv · 2406.05229

Phonon-induced renormalization of exchange interactions in metallic two-dimensional magnets

Danis I. Badrtdinov·Mikhail I. Katsnelson·Alexander N. Rudenko
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Abstract

The presence of spin-polarized charge carriers in metallic magnets provides a mechanism for spin-lattice interactions mediated by electron-phonon coupling. Here, we present a theory of this mechanism used to estimate its effect on the exchange interactions in 2D magnets. Starting from a square lattice model at half filling, we show that the presence of electron-phonon coupling with equilibrium phonon distribution leads to a notable suppression of exchange interactions with temperature. We then apply our approach to the prototypical 2D metallic ferromagnet, Fe$_3$GeTe$_2$, with moderate electron-phonon coupling. We find that the exchange interactions undergo a renormalization, leading to a softening of the magnon modes, and suppression of the Curie temperature by $\sim$10\%. We expect that this effect can be further enhanced in systems with strong electron-phonon coupling, as well as for non-equilibrium distribution of phonons induced by strong laser fields or charge currents.

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Danis I. Badrtdinov, Mikhail I. Katsnelson, Alexander N. Rudenko. 2024-06-07. Phonon-induced renormalization of exchange interactions in metallic two-dimensional magnets. https://doi.org/10.1103/physrevb.110.l060409

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