We derive the spin-wave dynamics in crystals from the time-dependent variational principle, which involves Berry phase terms as well as the energy of frozen spin waves. The general formulation is based on the adiabatic and harmonic approximations. Formulas for ferromagnets and antiferromagnets are derived in terms of Kohn-Sham wave functions, which are particularly suitable for practical ab initio calculations.
No takes yet. Share an insight, caveat, or question.
Niu et al. (1998) studied this question.
Synapse has enriched 4 closely related papers on similar clinical questions. Consider them for comparative context: