Magnon-phonon hybridization in quasi-2D antiferromagnet MnPSe$_3$

TL;DR

This study reveals magnon-phonon hybridization in MnPSe$_3$, a 2D antiferromagnetic van der Waals material, using magneto-Raman spectroscopy and theoretical modeling, with implications for spin transport in magnetic 2D materials.

Contribution

First observation of magnon-phonon hybridization in a 2D vdW antiferromagnet supported by experimental and theoretical analysis.

Findings

Identification of magnon-phonon hybridization in MnPSe$_3$

Temperature-dependent avoided crossing in phonon frequencies

Model reproduces hybridization behavior

Abstract

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$_\mathrm{g}$ phonons in MnPSe$_3$, a magnetic vdW material that could potentially host 2D 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. The strong magnon-phonon hybridization reported here highlights the need to understand its effects on spin transport experiments in magnetic vdW materials.