Magnon-Phonon Hybridization in a 2D Antiferromagnet MnPSe₃

Magnetic excitations in van der Waals (vdW) materials, especially in the two-dimensional (2D) limit, are an exciting research topic from both the fundamental and applied perspectives. Using temperature-dependent, magneto-Raman spectroscopy, we identify the hybridization of two-magnon excitations with two separate E_g phonons in MnPSe₃, a magnetic vdW material that hosts in-plane antiferromagnetism. Results from first principles calculations of the phonon and magnon spectra further support our identification. The Raman spectra’s rich temperature dependence through the magnetic transition displays an avoided-crossing behavior in the phonons’ frequency and a concurrent decrease in their lifetimes. We construct a model based on the interaction between a discrete level and a continuum that reproduces these observations. Our results imply a strong hybridization between two discrete phonons and a two-magnon continuum and demonstrates that the magnon-phonon interactions can be observed directly in Raman scattering to provide deep insight into these interactions in 2D magnetic materials. We also systematically study the overall Raman scattering intensity enhancement in the AFM phase. Our experimental and theoretical results point to the cause of spin-ordering-induced resonant Raman scattering effect in MnPSe₃.