Antiferromagnetism by the Spin Wave Method I: The Energy Levels

作者：John Michael Ziman · 发表于：Proceedings of the Physical Society Section A · 年份：1952 · DOI：10.1088/0370-1298/65/7/309 · 被引用次数：70 · 研究领域：Magnetic properties of thin films、Magneto-Optical Properties and Applications、Multiferroics and related materials

The Hamiltonian operator for an exchange antiferromagnet is expressed in terms of the deviations of the spins from the basic ordered antiparallel arrangement By a Fourier transformation the Hamiltonian may be approximately represented as a sum of harmonic oscillator terms, corresponding to spin waves. The role of anisotropy energy in fixing the domain axis is discussed, and the energy levels are calculated for the case of an external field parallel to this axis The ground-state energy includes the zero-point energy of the spin waves and is in good agreement with other theories Formulae are quoted for a Hamiltonian including dipole-dipole interaction between non-isotropic spins