Abstract
Fermionic structure of the spin-wave interaction vertex within the Hubbard-model representation of a quantum magnet is presented in a scheme that systematically preserves the spin-rotational symmetry and hence the Goldstone mode. We evaluate the diagrams contributing to the interaction vertex for the case of a quantum antiferromagnet in the strong-coupling limit. The exact cancellation of the leading-order contributions (of order U), as required by spin-rotational symmetry, is demonstrated.
- Received 17 May 1993
DOI:https://doi.org/10.1103/PhysRevB.48.10546
©1993 American Physical Society