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arXiv · 2212.09516

First-principles study of the gap in the spin excitation spectrum of the CrI$_3$ honeycomb ferromagnet

Tommaso Gorni·Oscar Baseggio·Pietro Delugas·Iurii Timrov·Stefano Baroni
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Abstract

The nature of the gap observed at the zone border in the spin-excitation spectrum of CrI$_3$ quasi-2D single crystals is still controversial. We perform first-principles calculations based on time-dependent density-functional perturbation theory, which indicate that the observed gap results from a combination of spin-orbit and inter-layer interaction effects. The former give rise to the anisotropic spin-spin interactions that are responsible for its very existence, while the latter determine both its displacement from the K point of the Brillouin zone due to the in-plane lattice distortions induced by them, and an enhancement of its magnitude, in agreement with experiments and previous theoretical work based on a lattice model.

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Tommaso Gorni, Oscar Baseggio, Pietro Delugas, Iurii Timrov, Stefano Baroni. 2022-12-19. First-principles study of the gap in the spin excitation spectrum of the CrI$_3$ honeycomb ferromagnet. https://doi.org/10.1103/physrevb.107.l220410

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