Physical review. B, Condensed matter
Effect of small interchain coupling on one-dimensional antiferromagnetic quantum Heisenberg spin systems: The integer-spin case
Mohamed Moussadek Azzouz, Benoît Douçot
Abstract
A two-dimensional array of weakly coupled antiferromagnetic spin chains is investigated using the Schwinger-boson technique. This method is known to give a good description of integer spins already at the mean-field level. We find that a finite coupling is necessary to introduce long-range antiferromagnetic order, consistently with the presence of a gap for a single chain. The energy gap and spin-spin correlations are calculated. These calculations correspond to the behavior of a nonlinear \ensuremath{\sigma} model without the one-dimensional topological term.