@article{lindg1976a,
title = {Bose Operator Expansions of Tensor Operators in the Theory of Magnetism},
language = {eng},
author = {LindgĂ„rd, Per-Anker and Kowalska, A.},
journal = {Journal of Physics C: Solid State Physics},
volume = {9},
number = {11},
pages = {2081-2092},
year = {1976},
issn = {17473802, 00223719},
abstract = {For pt.I see ibid., vol.7, p.1523 (1974). The matching of matrix element method is used to find a new self-consistent Bose operator expansion for tensor operators in spin systems with isotropic exchange interaction plus anisotropy. Tables are given for all tensor operators relevant for cubic and hexagonal symmetry. A discussion of renormalized spin-wave theory for a system with planar anisotropy shows that the Goldstone theorem is rigorously fulfilled to the considered order of perturbation. It is finally shown that the new expansion introduces wavevector-dependent terms from the single-ion anisotropy into the dispersion relation.},
doi = {10.1088/0022-3719/9/11/016}
}