[19p-P06-1~50] 10 Spintronics and Magnetics (Poster)

English Presentation

[19p-P06-16] Effects of Magnon Spin-Polarization on Magnon Lifetime in Antiferromagnetic Insulator NiO

〇(D)Andi Gumarilang Ahmadi¹, Nawa Kenji¹, Nakamura Kohji¹ (1.Mie Univ.)

Keywords:

Magnonics,Spin-Polarization,Antiferromagnets

Antiferromagnetic insulator NiO allows long-lifetime THz signal to propagate via two non-degenerate magnon modes that carry spin-polarization. Due to weak spin-orbital effects and insulating properties, the main channel that gives rise to magnon lifetime in NiO is four-magnons interactions. In this presentation, we investigate the effects of magnon spin-polarization on magnon lifetime driven by four-magnon interactions. Fourth order magnon Hamiltonian is treated as a perturbation term, and the inverse of imaginary part of self-energy in many-body Green’s functions is calculated. Room-temperature magnon lifetimes is calculated, and we confirm the experiment results. Static magnetic field is applied to the system, and the effects on magnon lifetime is observed. By comparing the response of magnon lifetime and magnon spin-polarization on static magnetic field, we find that the enhancement of magnon spin-polarization increases transition probability from one magnon state to another, which thus leads to the decrease of magnon lifetimes in one magnon state.