Eur. Phys. J. B 49, 187-194 (2006)
https://doi.org/10.1140/epjb/e2006-00052-x

Magnetic properties of antiferromagnetic quantum Heisenberg spin systems with a strict single particle site occupation

Laboratoire de Physique Théorique, UMR 7085 CNRS/ULP, 67084 Strasbourg Cedex, France

Corresponding authors: ^a rdillen@lpt1.u-strasbg.fr - ^b richert@lpt1.u-strasbg.fr

Received: 2 November 2005
Revised: 5 January 2006
Published online: 17 February 2006

Abstract

We work out the magnetization and susceptibility of Heisenberg- and XXZ-model antiferromagnet spin-1/2 systems in D dimensions under a rigorous constraint of single particle site occupancy. Quantum and thermal fluctuations are taken into account up to the first order in a loop expansion beyond the Néel state mean field solution. We discuss the results, their validity in the vicinity of the critical point and compare them with the results obtained by means of a spin wave approach.