Eur. Phys. J. B (2013) 86: 392
https://doi.org/10.1140/epjb/e2013-40001-0

Regular Article

Ground state properties of the ferrimagnetic one and two-dimensional Heisenberg model: Influence of dimerization and competitive interactions

Departamento de Física, Universidade Federal de Minas Gerais, CP 702, 30123-970 Belo Horizonte, MG, Brazil

^a e-mail: rodrigophc@gmail.com

Received: 1 January 2013
Received in final form: 18 April 2013
Published online: 23 September 2013

Abstract

We use the Schwinger boson mean field theory to study the effect of frustration and dimerization in the quantum ferrimagnetic model in one and two-dimensions. We calculate the spin reduction, the gap of the antiferromagnetic branch, and the spin fluctuation at T = 0 K. At finite temperature, the long-range order is destroyed because of the disappearance of the Bose condensation. The free energy, the magnetic susceptibility and the spin correlations at T = 0 K, are calculated. The effects of frustration and dimerization are discussed.