Strong phonon-magnon coupling of an O/Fe(001) surface

作者：Yan Zhu,YanFei Pan,JiYu Fan,ChunLan Ma,Jun Hu,XinYuan Wei,KaiCheng Zhang,HongBin Zhang

摘要：Using density functional calculations,we elucidate the interaction between magnons and phonons on Fe(001)and O/Fe(001)surfaces.The effective Heisenberg exchange parameters between neighbor sites(Ji)were derived by fitting the ab initio spin spiral dispersion relation to a classical Heisenberg model.In bulk Fe,J5bhas a larger amplitude than J2b-J4b.Surface magnons were softer on the Fe(001)surface than in bulk,but were strengthened on the O/Fe(001)surface through strong interactions between the O and Fe atoms.The four calculated high-energy phonon modes of O/Fe(001)excellently agreed with the experimental measurements.The J1in O/Fe(001)decreased significantly with increasing phonon amplitude.Phonon-magnon coupling occurred more easily on O/Fe(001)than on Fe(001).The softening of the magnon on the O/Fe(001)with phonon amplitude was attributed to the reduced amplitude of longitudinal excitations.Magnetic moment of the Fe atom of the second layer(Fe2)was especially sensitive to phonon amplitude,regardless of the motion direction of the Fe2 atoms.

发文机构：College of Science Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application College of Physics State Key Laboratory of Surface Physics and Key Laboratory for Computational Physical Sciences（MOE）&Department of Physics College of Mathematics and Physics Institute of Materials Science

关键词：phonon-magnoncouplingdensityfunctionaltheory(DFT)spinspiralO/Fe(001)

分类号： O469[理学—凝聚态物理]