2007/02/26 by E. Meloche, M. L. Plumer, C. M. Pinciuc
Materials Science · Mathematics · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Antiferromagnetism #Condensed matter physics #Excitation #Ferromagnetism #Formalism (music) #Geometry #Materials science #Mathematics #Multiferroics and related materials #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin wave #Surface (topology) #Thin film #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.76.214402
24 pages, 9 figures
arxiv created 2007/02/26 · openalex publication_date 2007/12/05 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Results are presented for spin-wave dispersions in geometrically frustrated stacked triangular antiferromagnets with a thin film or semi-infinite geometry having either zero, easy-plane, or easy-axis anisotropy. Surface effects on the equilibrium spin configurations and excitation spectrum are investigated for the case of antiferromagnetically coupled films, serving to extend previous results on ferromagnetically coupled layers [E. Meloche et al., Phys. Rev. B. 74, 094424 (2006)]. An operator equation of motion formalism is applied to systems which are quasi-one- and quasi-two-dimensional in character. In contrast to the case of ferromagnetically coupled films, the results of this work show surface modes that are well separated in frequency from bulk excitations. Magnetic excitations in thin films with an even or an odd number of layers show qualitatively different behavior. These results are relevant for a wide variety of stacked triangular antiferromagnetic materials.