Magneto-Raman Study of Magnon–Phonon Coupling in Two-Dimensional Ising Antiferromagnetic FePS3

• Published in: The journal of physical chemistry letters 2022-02, Vol.13 (6), p.1533-1539
• Main Authors: Sun, Yu-Jia, Lai, Jia-Min, Pang, Si-Min, Liu, Xue-Lu, Tan, Ping-Heng, Zhang, Jun
• Format: Article
• Language: English
• Subjects: Physical Insights into Light Interacting with Matter
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.2c00023

Recently, the coupling between magnons (quanta of spin waves) and phonons (quanta of lattice vibrations) in two-dimensional (2D) antiferromagnet FePS3 offers a myriad of applications ranging from spintronic devices to quantum information technologies. However, the reported magnon–phonon coupling in the FePS3 flake using Raman measurements requires an ultrahigh magnetic field up to 30 T. Here, we investigate the magnon–phonon coupling in FePS3 by near-resonant magneto-Raman spectroscopy under a relatively small magnetic field (|H 0| ≤ 9 T). Under near-resonant excitation, we find more pronounced coupling effects that are absent in non-resonant excitation: three optical phonons sensitive to the applied magnetic field are resolved, two of which show a frequency anti-crossing coupling with magnon, while the other coupled phonon exhibits only a polarization-coupled character without frequency anti-crossing. Besides, our polarized Raman results also show the polarization transferring between coupled magnon–phonon modes. On the basis of a modified theoretical model, we can well explain the measured Raman spectra.