Department of Physics, Grand Valley State University, Allendale, MI 49401, USA.
J Phys Condens Matter. 2011 Feb 2;23(4):046001. doi: 10.1088/0953-8984/23/4/046001. Epub 2011 Jan 7.
The magnetic phase diagram of a spatially anisotropic, frustrated spin-[Formula: see text] Heisenberg antiferromagnet on a stacked square lattice is investigated using a second-order spin-wave expansion. The effects of interlayer coupling and the spatial anisotropy on the magnetic ordering of two ordered ground states are explicitly studied. It is shown that with increase in next nearest neighbor frustration the second-order corrections play a significant role in stabilizing the magnetization. We obtain two ordered magnetic phases (Néel and stripe) separated by a paramagnetic disordered phase. Within the second-order spin-wave expansion we find that the width of the disordered phase diminishes with increase in the interlayer coupling or with decrease in spatial anisotropy but it does not disappear. Our obtained phase diagram differs significantly from the phase diagram obtained using linear spin-wave theory.
采用二阶自旋波展开方法研究了堆积正方形晶格上各向异性、受挫的自旋-[Formula: see text]海森堡反铁磁体的磁相图。明确研究了层间耦合和各向异性对两种有序基态磁有序的影响。结果表明，随着最近邻受挫的增加，二阶修正在稳定磁化方面起着重要作用。我们得到了两个有序的磁相（奈尔相和条纹相），它们被无序的磁相隔开。在二阶自旋波展开中，我们发现无序相的宽度随着层间耦合的增加或各向异性的减小而减小，但不会消失。我们得到的相图与使用线性自旋波理论得到的相图有很大的不同。
