Coherent Spin-Phonon Coupling in the Layered Ferrimagnet Mn3Si2Te6

TL;DR

This study demonstrates coherent spin-phonon coupling in Mn3Si2Te6, revealing how ultrafast photoexcitation influences lattice and spin dynamics, with implications for dynamic control of van der Waals magnets.

Contribution

It provides experimental evidence of coherent spin-phonon interactions and highlights the role of magneto-structural coupling in layered ferrimagnetic materials.

Findings

Lattice stiffening below magnetic transition temperature

Exchange-mediated lattice contraction observed

Spin relaxation channels involve phonon scattering

Abstract

We utilize ultrafast photoexcitation to drive coherent lattice oscillations in the layered ferrimagnetic crystal Mn3Si2Te6, which significantly stiffen below the magnetic ordering temperature. We suggest that this is due to an exchange-mediated contraction of the lattice, stemming from strong magneto-structural coupling in this material. Additionally, simulations of the transient incoherent dynamics reveal the importance of spin relaxation channels mediated by optical and acoustic phonon scattering. Our findings highlight the importance of spin-lattice coupling in van der Waals magnets and a promising route for their dynamic optical control through their intertwined electronic, lattice, and spin degrees of freedom.