Open AccessEffect of optical phonon-magnon interaction on the magnon life-time at finite temperature
Author(s) -
Cheng Tai-Min,
Luo Hong-Chao,
Liqi Lin
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.6531
Subject(s) - magnon , condensed matter physics , phonon , physics , brillouin zone , magnetic damping , ferromagnetism , quantum mechanics , vibration
A magnon-phonon interaction model is set up in a two-dimensional ferromagnetic double square-lattice system. By using the Matsubara Green function theory we have studied the magnon life-time of the system, calculated the magnon damping curves on the main symmetric line in the Brillouin zone, compared the influences of magnetic ion optical-mode phonon and non-magnetic ion optical-mode phonon on the magnon damping of the system, and discussed the influences of the parameter variations and temperature on the magnon damping. The results show that the coupling of the optical-mode phonon and magnon plays the main role in the magnon damping, especially, the longitudinal optical-mode phonon contributes the most for the magnon damping. It is also found that the effect of the nonmagnetic ion on magnon damping is more significant than that of the magnetic ion. According to the expression -ImΣ*(1)(k)=/(2τ), the magnon life-time is discussed.