Relation between spin-coherent states and boson-coherent states in the theory of magnetism

Abstract

It is shown that the application of both the spin-coherent states and the Holstein-Primakoff representation with boson-coherent states leads to the same classical limit for the spin-operator average values, if the proper procedure for normal ordering is applied. A general expression for the boson expansion is derived, and the first quantum correction is obtained. Consequences of the study of nonlinear excitations in magnetic systems are presented.