We find unusually large cross-polarized (and anti-symmetric) Raman signature of Ag phonon mode in CrI3, in agreement with experiments. The signal is present only when the following three effects are considered in concert: ferromagnetism on Cr atoms, spin-orbit interaction, and resonant effects. Somewhat surprisingly, we find that the relevant spin-orbit interaction potential originates from iodine atoms, despite magnetism being mostly on chromium atoms. We analyze the Raman signature as a function of magnetic order, the direction of the magnetic moment, energy and polarization of light used for Raman scattering, as well as carrier lifetime. In addition to a strong cross-polarized Raman signal, we also find unusually strong phonon modulated magneto-optical Kerr effect (MOKE) in CrI3.
@article{arxiv.2010.06633,
title = {Large cross-polarized Raman signal in CrI$_3$: A first-principles study},
author = {Ming Lei and Sinisa Coh},
journal= {arXiv preprint arXiv:2010.06633},
year = {2021}
}