Understanding and controlling magnon relaxation in two-dimensional (2D) ferromagnets is crucial for applications in spintronics, as it governs magnon-based spin transport and device performance. However, existing studies have been largely confined to systems with low Curie temperatures, leaving near-room-temperature 2D ferromagnets rarely explored. Here, we combine spin-wave theory with first-principles calculations to investigate magnon relaxation in the room-temperature 2D ferromagnet ${\mathrm{MnSe}}_2$, considering both magnon-magnon interactions (MMIs) and magnon-phonon interactions (MPIs) and analyzing their effects under external strain and magnetic fields. We find that a MPI exhibits a strong, nonmonotonic strain dependence due to its coupling to lattice distortions, whereas a MMI is primarily controlled by magnetic fields and is insensitive to strain. At room temperature, a MMI dominates the relaxation process, while the dominant mechanism can be largely reversed by strain and magnetic fields, especially at low temperatures and large wave vectors. These findings highlight the complementary roles of MPIs and MMIs in ${\mathrm{MnSe}}_2$, offering potential strategies for tailoring magnon relaxation in magnon-based spintronic devices.

Close

PrevNext

View figure in article

• Magnons
• Phonons
• Spin waves
• 2-dimensional systems
• Ferromagnets
• First-principles calculations
• Mean field theory
• Monte Carlo methods
• Spin wave theory