Mai Thuc T, Garrity Kevin F, McCreary Amber, Argo Joshua, Simpson Jeffrey R, Doan-Nguyen Vicky, Aguilar Rolando Valdés, Walker Angela R Hight
Nanoscale Device Characterization Division, Physical Measurement Laboratory, NIST, Gaithersburg, MD 20899, USA.
Materials Measurement Science Division, Materials Measurement Laboratory, NIST, Gaithersburg, MD 20899, USA.
Sci Adv. 2021 Oct 29;7(44):eabj3106. doi: 10.1126/sciadv.abj3106.
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 phonons in manganese phosphorus triselenide (MnPSe), 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 each phonon and a two-magnon continuum. This work demonstrates that the magnon-phonon interactions can be observed directly in Raman scattering and provides deep insight into these interactions in 2D magnetic materials.
范德华（vdW）材料中的磁激发，特别是在二维（2D）极限情况下，从基础和应用的角度来看都是一个令人兴奋的研究课题。利用温度依赖的磁拉曼光谱，我们在三硒化锰磷（MnPSe）中识别出两个磁振子激发与两个声子的杂化，MnPSe是一种具有面内反铁磁性的磁性vdW材料。声子和磁振子光谱的第一性原理计算结果进一步支持了我们的识别。通过磁转变，拉曼光谱丰富的温度依赖性在声子频率上表现出避免交叉行为，同时它们的寿命也会降低。我们基于离散能级与连续体之间的相互作用构建了一个模型，该模型再现了这些观测结果。我们的结果表明每个声子与一个双磁振子连续体之间存在强烈的杂化。这项工作表明，磁振子 - 声子相互作用可以在拉曼散射中直接观察到，并为二维磁性材料中的这些相互作用提供了深入的见解。
