Parreira J. R., Bolina O., Perez J. F.
Neel Order in the Ground State of Spin-1/2 Heisenberg 
Antiferromagnetic Multilayer Systems
(10K, LaTeX)

ABSTRACT.  We show the existence of Neel order for the ground state of a system
composed by M two-dimensional layers with spin-1/2 and Heisenberg
antiferromagnetic coupling, provided M \geq 8. The method uses the
infrared bounds for the ground state combined with the ideas introduced
by Kennedy, Lieb and Shastry.