The discovery of 2-dimensional (2D) materials, such as CrI3, that retain magnetic ordering at monolayer thickness has resulted in a surge of research in 2D magnetism from both pure and applied perspectives. Here, we report a magneto-Raman spectroscopy study on multilayered CrI3, focusing on two new features in the spectra which appear at temperatures below the magnetic ordering temperature and were previously assigned to high frequency magnons. We observe a striking evolution of the Raman spectra with increasing magnetic field in which clear, sudden changes in intensities of the modes are attributed to the interlayer ordering changing from antiferromagnetic to ferromagnetic at a critical magnetic field. Our work highlights the sensitivity of the Raman modes to weak interlayer spin ordering in CrI3. In addition, we theoretically examine potential origins for the new modes, which we deduce are unlikely single magnons.
@article{arxiv.1910.01237,
title = {Distinct magneto-Raman signatures of spin-flip phase transitions in CrI3},
author = {Amber McCreary and Thuc T. Mai and Franz G. Utermohlen and Jeffrey R. Simpson and Kevin F. Garrity and Xiaozhou Feng and Dmitry Shcherbakov and Yanglin Zhu and Jin Hu and Daniel Weber and Kenji Watanabe and Takashi Taniguchi and Joshua E. Goldberger and Zhiqiang Mao and Chun Ning Lau and Yuanming Lu and Nandini Trivedi and Rolando Valdés Aguilar and Angela R. Hight Walker},
journal= {arXiv preprint arXiv:1910.01237},
year = {2020}
}