J. Phys. I France
Volume 2, Number 4, April 1992
Page(s) 371 - 377
DOI: 10.1051/jp1:1992149
J. Phys. I France 2 (1992) 371-377

Self-consistent interaction of magnons in a frustrated quantum antiferromagnet

L. Bergomi and Th. Jolicoeur

Service de Physique Théorique, C.E. Saclay, F-91191 Gif-sur-Yvette Cedex, France

(Received 19 December 1991, accepted 27 January 1992)

We study the magnon interactions by means of a self-consistent calculation in a frustrated quantum Heisenberg antiferromagnet with first and second neighbor exchange couplings. We have used the Hartree-Fock-Bogolyubov scheme at zero temperature. The effect of frustration on the shape of the spin-wave spectrum is investigated: we find a strong decrease of the spin-wave velocity. A clear deviation from spin wave theory is found when comparing with finite lattice results.

© Les Editions de Physique 1992