Green's-Function Theory of Magnon Instabilities
U. Balucani, F. Barocchi, V. Tognetti, G. Brunner · Physical review. B, Solid state · 1972
The parallel-pumping and second-order Suhl magnon instabilities are treated by means of the many-time Green's-function method. The criterion for determining the threshold field as the radius of convergence of a series of the physical quantities, established for the first-order Suhl instability, is also found to be valid in these cases.