Magnetic order and spin excitations in layered Heisenberg antiferromagnets with compass-model anisotropies
A. A. Vladimirov, D. Ihle+, N. M. Plakida
Joint Institute for Nuclear Research, 141980 Dubna, Russia
+Institut für Theoretische Physik, Universität Leipzig, D-04109 Leipzig, Germany
Abstract
The spin-wave excitation spectrum, the magnetization,
and the Néel temperature for the quasi-two-dimensional
spin-1/2 antiferromagnetic Heisenberg model with compass-model
interaction in the plane proposed for iridates are calculated in
the random phase approximation. The spin-wave spectrum agrees
well with data of Lanczos diagonalization. We find that the
Néel temperature is enhanced by the compass-model interaction
and is close to the experimental value for Ba2IrO4.